diff --git a/src/libs/languageserverprotocol/client.h b/src/libs/languageserverprotocol/client.h
index 830d1caae43..4c04c2a90e8 100644
--- a/src/libs/languageserverprotocol/client.h
+++ b/src/libs/languageserverprotocol/client.h
@@ -33,7 +33,7 @@ class Registration : public JsonObject
 {
 public:
     Registration() : Registration(QString()) {}
-    Registration(const QString &method)
+    explicit Registration(const QString &method)
     {
         setId(QUuid::createUuid().toString());
         setMethod(method);
@@ -58,7 +58,8 @@ class RegistrationParams : public JsonObject
 {
 public:
     RegistrationParams() : RegistrationParams(QList<Registration>()) {}
-    RegistrationParams(const QList<Registration> &registrations) { setRegistrations(registrations); }
+    explicit RegistrationParams(const QList<Registration> &registrations)
+    { setRegistrations(registrations); }
     using JsonObject::JsonObject;
 
     QList<Registration> registrations() const { return array<Registration>(registrationsKey); }
@@ -73,7 +74,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT RegisterCapabilityRequest : public Request<
         std::nullptr_t, std::nullptr_t, RegistrationParams>
 {
 public:
-    RegisterCapabilityRequest(const RegistrationParams &params);
+    explicit RegisterCapabilityRequest(const RegistrationParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "client/registerCapability";
 };
@@ -111,7 +112,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT UnregisterCapabilityRequest : public Request
         std::nullptr_t, std::nullptr_t, UnregistrationParams>
 {
 public:
-    UnregisterCapabilityRequest(const UnregistrationParams &params);
+    explicit UnregisterCapabilityRequest(const UnregistrationParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "client/unregisterCapability";
 };
diff --git a/src/libs/languageserverprotocol/completion.h b/src/libs/languageserverprotocol/completion.h
index 4e8d34d1c91..013136b58a0 100644
--- a/src/libs/languageserverprotocol/completion.h
+++ b/src/libs/languageserverprotocol/completion.h
@@ -249,14 +249,14 @@ class LANGUAGESERVERPROTOCOL_EXPORT CompletionResult
 {
 public:
     using variant::variant;
-    CompletionResult(const QJsonValue &value);
+    explicit CompletionResult(const QJsonValue &value);
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT CompletionRequest : public Request<
         CompletionResult, std::nullptr_t, CompletionParams>
 {
 public:
-    CompletionRequest(const CompletionParams &params);
+    explicit CompletionRequest(const CompletionParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/completion";
 };
@@ -265,7 +265,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT CompletionItemResolveRequest : public Reques
         CompletionItem, std::nullptr_t, CompletionItem>
 {
 public:
-    CompletionItemResolveRequest(const CompletionItem &params);
+    explicit CompletionItemResolveRequest(const CompletionItem &params);
     using Request::Request;
     constexpr static const char methodName[] = "completionItem/resolve";
 };
diff --git a/src/libs/languageserverprotocol/diagnostics.h b/src/libs/languageserverprotocol/diagnostics.h
index 7525871b051..68ede706db5 100644
--- a/src/libs/languageserverprotocol/diagnostics.h
+++ b/src/libs/languageserverprotocol/diagnostics.h
@@ -49,7 +49,7 @@ public:
 class LANGUAGESERVERPROTOCOL_EXPORT PublishDiagnosticsNotification : public Notification<PublishDiagnosticsParams>
 {
 public:
-    PublishDiagnosticsNotification(const PublishDiagnosticsParams &params);
+    explicit PublishDiagnosticsNotification(const PublishDiagnosticsParams &params);
     using Notification::Notification;
     constexpr static const char methodName[] = "textDocument/publishDiagnostics";
 };
diff --git a/src/libs/languageserverprotocol/icontent.h b/src/libs/languageserverprotocol/icontent.h
index f1c02f5a1a2..33ef876510b 100644
--- a/src/libs/languageserverprotocol/icontent.h
+++ b/src/libs/languageserverprotocol/icontent.h
@@ -47,17 +47,17 @@ class LANGUAGESERVERPROTOCOL_EXPORT MessageId : public Utils::variant<int, QStri
 {
 public:
     MessageId() = default;
-    MessageId(int id) : variant(id) {}
-    MessageId(QString id) : variant(id) {}
+    explicit MessageId(int id) : variant(id) {}
+    explicit MessageId(const QString &id) : variant(id) {}
     explicit MessageId(const QJsonValue &value)
     {
         if (value.isUndefined())
             return;
         QTC_CHECK(value.isDouble() || value.isString());
         if (value.isDouble())
-            *this = value.toInt();
+            *this = MessageId(value.toInt());
         else if (value.isString())
-            *this = value.toString();
+            *this = MessageId(value.toString());
     }
 
     QJsonValue toJson() const
diff --git a/src/libs/languageserverprotocol/initializemessages.h b/src/libs/languageserverprotocol/initializemessages.h
index 700caf85373..eee4de5d396 100644
--- a/src/libs/languageserverprotocol/initializemessages.h
+++ b/src/libs/languageserverprotocol/initializemessages.h
@@ -129,7 +129,7 @@ using InitializedParams = JsonObject;
 class LANGUAGESERVERPROTOCOL_EXPORT InitializeNotification : public Notification<InitializedParams>
 {
 public:
-    InitializeNotification(const InitializedParams &params);
+    explicit InitializeNotification(const InitializedParams &params);
     using Notification::Notification;
     constexpr static const char methodName[] = "initialized";
 
@@ -173,7 +173,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT InitializeRequest : public Request<
         InitializeResult, InitializeError, InitializeParams>
 {
 public:
-    InitializeRequest(const InitializeParams &params = InitializeParams());
+    explicit InitializeRequest(const InitializeParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "initialize";
 };
diff --git a/src/libs/languageserverprotocol/jsonrpcmessages.h b/src/libs/languageserverprotocol/jsonrpcmessages.h
index b5d36e4c4f9..f97ed803fc6 100644
--- a/src/libs/languageserverprotocol/jsonrpcmessages.h
+++ b/src/libs/languageserverprotocol/jsonrpcmessages.h
@@ -46,8 +46,8 @@ class LANGUAGESERVERPROTOCOL_EXPORT JsonRpcMessage : public IContent
 {
 public:
     JsonRpcMessage();
-    JsonRpcMessage(const QJsonObject &jsonObject);
-    JsonRpcMessage(QJsonObject &&jsonObject);
+    explicit JsonRpcMessage(const QJsonObject &jsonObject);
+    explicit JsonRpcMessage(QJsonObject &&jsonObject);
 
     QByteArray toRawData() const final;
     QByteArray mimeType() const final;
@@ -94,8 +94,8 @@ public:
         setParams(params);
     }
 
-    Notification(const QJsonObject &jsonObject) : JsonRpcMessage(jsonObject) {}
-    Notification(QJsonObject &&jsonObject) : JsonRpcMessage(std::move(jsonObject)) {}
+    explicit Notification(const QJsonObject &jsonObject) : JsonRpcMessage(jsonObject) {}
+    explicit Notification(QJsonObject &&jsonObject) : JsonRpcMessage(std::move(jsonObject)) {}
 
     QString method() const
     { return fromJsonValue<QString>(m_jsonObject.value(methodKey)); }
@@ -134,7 +134,7 @@ class Notification<std::nullptr_t> : public JsonRpcMessage
 {
 public:
     Notification() : Notification(QString()) {}
-    Notification(const QString &methodName, const std::nullptr_t &/*params*/ = nullptr)
+    explicit Notification(const QString &methodName, const std::nullptr_t &/*params*/ = nullptr)
     {
         setMethod(methodName);
         setParams(nullptr);
@@ -270,9 +270,9 @@ class Request : public Notification<Params>
 public:
     Request(const QString &methodName, const Params &params)
         : Notification<Params>(methodName, params)
-    { setId(QUuid::createUuid().toString()); }
-    Request(const QJsonObject &jsonObject) : Notification<Params>(jsonObject) { }
-    Request(QJsonObject &&jsonObject) : Notification<Params>(std::move(jsonObject)) { }
+    { setId(MessageId(QUuid::createUuid().toString())); }
+    explicit Request(const QJsonObject &jsonObject) : Notification<Params>(jsonObject) { }
+    explicit Request(QJsonObject &&jsonObject) : Notification<Params>(std::move(jsonObject)) { }
 
     MessageId id() const
     { return MessageId(JsonRpcMessage::m_jsonObject.value(idKey)); }
@@ -323,7 +323,7 @@ private:
 class LANGUAGESERVERPROTOCOL_EXPORT CancelParameter : public JsonObject
 {
 public:
-    CancelParameter(const MessageId &id) { setId(id); }
+    explicit CancelParameter(const MessageId &id) { setId(id); }
     CancelParameter() = default;
     using JsonObject::JsonObject;
 
@@ -343,7 +343,7 @@ public:
 class LANGUAGESERVERPROTOCOL_EXPORT CancelRequest : public Notification<CancelParameter>
 {
 public:
-    CancelRequest(const CancelParameter &params);
+    explicit CancelRequest(const CancelParameter &params);
     using Notification::Notification;
     constexpr static const char methodName[] = "$/cancelRequest";
 };
diff --git a/src/libs/languageserverprotocol/languagefeatures.h b/src/libs/languageserverprotocol/languagefeatures.h
index ee40187a71f..ab1834bbce0 100644
--- a/src/libs/languageserverprotocol/languagefeatures.h
+++ b/src/libs/languageserverprotocol/languagefeatures.h
@@ -106,7 +106,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT HoverRequest
     : public Request<Hover, std::nullptr_t, TextDocumentPositionParams>
 {
 public:
-    HoverRequest(const TextDocumentPositionParams &params = TextDocumentPositionParams());
+    explicit HoverRequest(const TextDocumentPositionParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/hover";
 };
@@ -201,7 +201,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT SignatureHelpRequest
     : public Request<LanguageClientValue<SignatureHelp>, std::nullptr_t, TextDocumentPositionParams>
 {
 public:
-    SignatureHelpRequest(const TextDocumentPositionParams &params = TextDocumentPositionParams());
+    explicit SignatureHelpRequest(const TextDocumentPositionParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/signatureHelp";
 };
@@ -211,7 +211,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT GotoResult
         : public Utils::variant<Location, QList<Location>, std::nullptr_t>
 {
 public:
-    GotoResult(const QJsonValue &value);
+    explicit GotoResult(const QJsonValue &value);
     using variant::variant;
 };
 
@@ -219,7 +219,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT GotoDefinitionRequest
     : public Request<GotoResult, std::nullptr_t, TextDocumentPositionParams>
 {
 public:
-    GotoDefinitionRequest(const TextDocumentPositionParams &params = TextDocumentPositionParams());
+    explicit GotoDefinitionRequest(const TextDocumentPositionParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/definition";
 };
@@ -228,8 +228,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT GotoTypeDefinitionRequest : public Request<
         GotoResult, std::nullptr_t, TextDocumentPositionParams>
 {
 public:
-    GotoTypeDefinitionRequest(
-            const TextDocumentPositionParams &params = TextDocumentPositionParams());
+    explicit GotoTypeDefinitionRequest(const TextDocumentPositionParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/typeDefinition";
 };
@@ -238,8 +237,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT GotoImplementationRequest : public Request<
         GotoResult, std::nullptr_t, TextDocumentPositionParams>
 {
 public:
-    GotoImplementationRequest(
-            const TextDocumentPositionParams &params = TextDocumentPositionParams());
+    explicit GotoImplementationRequest(const TextDocumentPositionParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/implementation";
 };
@@ -277,7 +275,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT FindReferencesRequest : public Request<
         LanguageClientArray<Location>, std::nullptr_t, ReferenceParams>
 {
 public:
-    FindReferencesRequest(const ReferenceParams &params = ReferenceParams());
+    explicit FindReferencesRequest(const ReferenceParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/references";
 };
@@ -310,7 +308,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DocumentHighlightsResult
 public:
     using variant::variant;
     DocumentHighlightsResult() : variant(nullptr) {}
-    DocumentHighlightsResult(const QJsonValue &value);
+    explicit DocumentHighlightsResult(const QJsonValue &value);
     using variant::operator=;
 };
 
@@ -318,8 +316,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DocumentHighlightsRequest : public Request<
         DocumentHighlightsResult, std::nullptr_t, TextDocumentPositionParams>
 {
 public:
-    DocumentHighlightsRequest(
-            const TextDocumentPositionParams &params = TextDocumentPositionParams());
+    explicit DocumentHighlightsRequest(const TextDocumentPositionParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/documentHighlight";
 };
@@ -328,7 +325,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT TextDocumentParams : public JsonObject
 {
 public:
     TextDocumentParams();
-    TextDocumentParams(const TextDocumentIdentifier &identifier);
+    explicit TextDocumentParams(const TextDocumentIdentifier &identifier);
     using JsonObject::JsonObject;
 
     TextDocumentIdentifier textDocument() const
@@ -348,7 +345,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DocumentSymbolsResult
 public:
     using variant::variant;
     DocumentSymbolsResult() : variant(nullptr) {}
-    DocumentSymbolsResult(const QJsonValue &value);
+    explicit DocumentSymbolsResult(const QJsonValue &value);
     DocumentSymbolsResult(const DocumentSymbolsResult &other) : variant(other) {}
     DocumentSymbolsResult(DocumentSymbolsResult &&other) : variant(std::move(other)) {}
 
@@ -370,7 +367,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DocumentSymbolsRequest
         : public Request<DocumentSymbolsResult, std::nullptr_t, DocumentSymbolParams>
 {
 public:
-    DocumentSymbolsRequest(const DocumentSymbolParams &params = DocumentSymbolParams());
+    explicit DocumentSymbolsRequest(const DocumentSymbolParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/documentSymbol";
 };
@@ -476,7 +473,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT CodeActionRequest : public Request<
         CodeActionResult, std::nullptr_t, CodeActionParams>
 {
 public:
-    CodeActionRequest(const CodeActionParams &params = CodeActionParams());
+    explicit CodeActionRequest(const CodeActionParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/codeAction";
 };
@@ -507,7 +504,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT CodeLensRequest : public Request<
         LanguageClientArray<CodeLens>, std::nullptr_t, CodeLensParams>
 {
 public:
-    CodeLensRequest(const CodeLensParams &params = CodeLensParams());
+    explicit CodeLensRequest(const CodeLensParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/codeLens";
 };
@@ -516,7 +513,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT CodeLensResolveRequest : public Request<
         CodeLens, std::nullptr_t, CodeLens>
 {
 public:
-    CodeLensResolveRequest(const CodeLens &params = CodeLens());
+    explicit CodeLensResolveRequest(const CodeLens &params);
     using Request::Request;
     constexpr static const char methodName[] = "codeLens/resolve";
 };
@@ -547,7 +544,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DocumentLinkRequest : public Request<
         LanguageClientValue<DocumentLink>, std::nullptr_t, DocumentLinkParams>
 {
 public:
-    DocumentLinkRequest(const DocumentLinkParams &params = DocumentLinkParams());
+    explicit DocumentLinkRequest(const DocumentLinkParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/documentLink";
 };
@@ -556,7 +553,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DocumentLinkResolveRequest : public Request<
         DocumentLink, std::nullptr_t, DocumentLink>
 {
 public:
-    DocumentLinkResolveRequest(const DocumentLink &params = DocumentLink());
+    explicit DocumentLinkResolveRequest(const DocumentLink &params);
     using Request::Request;
     constexpr static const char methodName[] = "documentLink/resolve";
 };
@@ -602,7 +599,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DocumentColorRequest : public Request<
         QList<ColorInformation>, std::nullptr_t, DocumentColorParams>
 {
 public:
-    DocumentColorRequest(const DocumentColorParams &params = DocumentColorParams());
+    explicit DocumentColorRequest(const DocumentColorParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/documentColor";
 };
@@ -656,7 +653,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT ColorPresentationRequest : public Request<
         QList<ColorPresentation>, std::nullptr_t, ColorPresentationParams>
 {
 public:
-    ColorPresentationRequest(const ColorPresentationParams &params = ColorPresentationParams());
+    explicit ColorPresentationRequest(const ColorPresentationParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/colorPresentation";
 };
@@ -665,8 +662,8 @@ class DocumentFormattingProperty : public Utils::variant<bool, double, QString>
 {
 public:
     DocumentFormattingProperty() = default;
-    DocumentFormattingProperty(const QJsonValue &value);
-    DocumentFormattingProperty(const DocumentFormattingProperty &other)
+    explicit DocumentFormattingProperty(const QJsonValue &value);
+    explicit DocumentFormattingProperty(const DocumentFormattingProperty &other)
         : Utils::variant<bool, double, QString>(other) {}
 
     using variant::variant;
@@ -713,7 +710,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DocumentFormattingRequest : public Request<
         LanguageClientArray<TextEdit>, std::nullptr_t, DocumentFormattingParams>
 {
 public:
-    DocumentFormattingRequest(const DocumentFormattingParams &params = DocumentFormattingParams());
+    explicit DocumentFormattingRequest(const DocumentFormattingParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/formatting";
 };
@@ -741,7 +738,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DocumentRangeFormattingRequest : public Requ
         LanguageClientArray<TextEdit>, std::nullptr_t, DocumentRangeFormattingParams>
 {
 public:
-    DocumentRangeFormattingRequest(const DocumentRangeFormattingParams &params = DocumentRangeFormattingParams());
+    explicit DocumentRangeFormattingRequest(const DocumentRangeFormattingParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/rangeFormatting";
 };
@@ -772,8 +769,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DocumentOnTypeFormattingRequest : public Req
         QList<TextEdit>, std::nullptr_t, DocumentFormattingParams>
 {
 public:
-    DocumentOnTypeFormattingRequest(
-            const DocumentFormattingParams &params = DocumentFormattingParams());
+    explicit DocumentOnTypeFormattingRequest(const DocumentFormattingParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/onTypeFormatting";
 };
@@ -803,7 +799,7 @@ public:
     PrepareRenameResult(const Utils::variant<PlaceHolderResult, Range, std::nullptr_t> &val);
     explicit PrepareRenameResult(const PlaceHolderResult &val);
     explicit PrepareRenameResult(const Range &val);
-    PrepareRenameResult(const QJsonValue &val);
+    explicit PrepareRenameResult(const QJsonValue &val);
 
     bool isValid(ErrorHierarchy *error) const;
 };
@@ -812,7 +808,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT PrepareRenameRequest
     : public Request<PrepareRenameResult, std::nullptr_t, TextDocumentPositionParams>
 {
 public:
-    PrepareRenameRequest(const TextDocumentPositionParams &params = TextDocumentPositionParams());
+    explicit PrepareRenameRequest(const TextDocumentPositionParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/prepareRename";
 };
@@ -840,7 +836,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT RenameRequest : public Request<
         WorkspaceEdit, std::nullptr_t, RenameParams>
 {
 public:
-    RenameRequest(const RenameParams &params = RenameParams());
+    explicit RenameRequest(const RenameParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/rename";
 };
@@ -849,7 +845,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT SemanticHighlightToken
 {
 public:
     // Just accepts token with 8 bytes
-    SemanticHighlightToken(const QByteArray &token);
+    explicit SemanticHighlightToken(const QByteArray &token);
     SemanticHighlightToken() = default;
 
     void appendToByteArray(QByteArray &byteArray) const;
@@ -898,7 +894,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT SemanticHighlightNotification
     : public Notification<SemanticHighlightingParams>
 {
 public:
-    SemanticHighlightNotification(const SemanticHighlightingParams &params);
+    explicit SemanticHighlightNotification(const SemanticHighlightingParams &params);
     using Notification::Notification;
     constexpr static const char methodName[] = "textDocument/semanticHighlighting";
 };
diff --git a/src/libs/languageserverprotocol/lsptypes.h b/src/libs/languageserverprotocol/lsptypes.h
index d1c0df7fa22..49f323f0404 100644
--- a/src/libs/languageserverprotocol/lsptypes.h
+++ b/src/libs/languageserverprotocol/lsptypes.h
@@ -65,7 +65,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT Position : public JsonObject
 public:
     Position() = default;
     Position(int line, int character);
-    Position(const QTextCursor &cursor);
+    explicit Position(const QTextCursor &cursor);
     using JsonObject::JsonObject;
 
     // Line position in a document (zero-based).
@@ -233,7 +233,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT TextDocumentIdentifier : public JsonObject
 {
 public:
     TextDocumentIdentifier() : TextDocumentIdentifier(DocumentUri()) {}
-    TextDocumentIdentifier(const DocumentUri &uri) { setUri(uri); }
+    explicit TextDocumentIdentifier(const DocumentUri &uri) { setUri(uri); }
     using JsonObject::JsonObject;
 
     // The text document's URI.
@@ -393,7 +393,7 @@ public:
     MarkupKind(const Value value)
         : m_value(value)
     {}
-    MarkupKind(const QJsonValue &value);
+    explicit MarkupKind(const QJsonValue &value);
 
     operator QJsonValue() const;
     Value value() const { return m_value; }
@@ -411,7 +411,7 @@ public:
     using JsonObject::JsonObject;
 
     // The type of the Markup
-    MarkupKind kind() const { return value(kindKey); }
+    MarkupKind kind() const { return MarkupKind(value(kindKey)); }
     void setKind(MarkupKind kind) { insert(kindKey, kind); }
     Qt::TextFormat textFormat() const
     { return kind() == MarkupKind::markdown ? Qt::MarkdownText : Qt::PlainText; }
@@ -428,7 +428,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT MarkupOrString : public Utils::variant<QStri
 {
 public:
     MarkupOrString() = default;
-    MarkupOrString(const Utils::variant<QString, MarkupContent> &val);
+    explicit MarkupOrString(const Utils::variant<QString, MarkupContent> &val);
     explicit MarkupOrString(const QString &val);
     explicit MarkupOrString(const MarkupContent &val);
     MarkupOrString(const QJsonValue &val);
diff --git a/src/libs/languageserverprotocol/lsputils.h b/src/libs/languageserverprotocol/lsputils.h
index 435d956eeb8..677325448bb 100644
--- a/src/libs/languageserverprotocol/lsputils.h
+++ b/src/libs/languageserverprotocol/lsputils.h
@@ -73,10 +73,10 @@ public:
 
     LanguageClientArray() {}
 
-    LanguageClientArray(const QList<T> &list)
+    explicit LanguageClientArray(const QList<T> &list)
     { *this = list; }
 
-    LanguageClientArray(const QJsonValue &value)
+    explicit LanguageClientArray(const QJsonValue &value)
     {
         if (value.isArray()) {
             QList<T> values;
diff --git a/src/libs/languageserverprotocol/messages.h b/src/libs/languageserverprotocol/messages.h
index 0c10b823db3..6a9580e3e56 100644
--- a/src/libs/languageserverprotocol/messages.h
+++ b/src/libs/languageserverprotocol/messages.h
@@ -56,7 +56,7 @@ public:
 class LANGUAGESERVERPROTOCOL_EXPORT ShowMessageNotification : public Notification<ShowMessageParams>
 {
 public:
-    ShowMessageNotification(const ShowMessageParams &params);
+    explicit ShowMessageNotification(const ShowMessageParams &params);
     using Notification::Notification;
     constexpr static const char methodName[] = "window/showMessage";
 };
@@ -90,7 +90,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT ShowMessageRequest : public Request<
         LanguageClientValue<MessageActionItem>, std::nullptr_t, ShowMessageRequestParams>
 {
 public:
-    ShowMessageRequest(const ShowMessageRequestParams &params);
+    explicit ShowMessageRequest(const ShowMessageRequestParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "window/showMessageRequest";
 };
@@ -100,7 +100,7 @@ using LogMessageParams = ShowMessageParams;
 class LANGUAGESERVERPROTOCOL_EXPORT LogMessageNotification : public Notification<LogMessageParams>
 {
 public:
-    LogMessageNotification(const LogMessageParams &params);
+    explicit LogMessageNotification(const LogMessageParams &params);
     using Notification::Notification;
     constexpr static const char methodName[] = "window/logMessage";
 };
@@ -108,7 +108,7 @@ public:
 class LANGUAGESERVERPROTOCOL_EXPORT TelemetryNotification : public Notification<JsonObject>
 {
 public:
-    TelemetryNotification(const JsonObject &params);
+    explicit TelemetryNotification(const JsonObject &params);
     using Notification::Notification;
     constexpr static const char methodName[] = "telemetry/event";
 
diff --git a/src/libs/languageserverprotocol/textsynchronization.cpp b/src/libs/languageserverprotocol/textsynchronization.cpp
index a8760eeae57..ec8ec0963f0 100644
--- a/src/libs/languageserverprotocol/textsynchronization.cpp
+++ b/src/libs/languageserverprotocol/textsynchronization.cpp
@@ -71,7 +71,7 @@ DidChangeTextDocumentParams::DidChangeTextDocumentParams(
         const VersionedTextDocumentIdentifier &docId, const QString &text)
 {
     setTextDocument(docId);
-    setContentChanges({text});
+    setContentChanges({TextDocumentContentChangeEvent(text)});
 }
 
 bool DidChangeTextDocumentParams::isValid(ErrorHierarchy *error) const
@@ -91,7 +91,7 @@ DidCloseTextDocumentParams::DidCloseTextDocumentParams(const TextDocumentIdentif
 }
 
 DidChangeTextDocumentParams::TextDocumentContentChangeEvent::TextDocumentContentChangeEvent(
-        const QString text)
+    const QString &text)
 {
     setText(text);
 }
diff --git a/src/libs/languageserverprotocol/textsynchronization.h b/src/libs/languageserverprotocol/textsynchronization.h
index 9656455d6fc..72746ad07de 100644
--- a/src/libs/languageserverprotocol/textsynchronization.h
+++ b/src/libs/languageserverprotocol/textsynchronization.h
@@ -34,7 +34,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DidOpenTextDocumentParams : public JsonObjec
 {
 public:
     DidOpenTextDocumentParams() = default;
-    DidOpenTextDocumentParams(const TextDocumentItem &document);
+    explicit DidOpenTextDocumentParams(const TextDocumentItem &document);
     using JsonObject::JsonObject;
 
     TextDocumentItem textDocument() const { return typedValue<TextDocumentItem>(textDocumentKey); }
@@ -49,7 +49,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DidOpenTextDocumentNotification : public Not
         DidOpenTextDocumentParams>
 {
 public:
-    DidOpenTextDocumentNotification(const DidOpenTextDocumentParams &params);
+    explicit DidOpenTextDocumentNotification(const DidOpenTextDocumentParams &params);
     using Notification::Notification;
     constexpr static const char methodName[] = "textDocument/didOpen";
 };
@@ -58,7 +58,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT TextDocumentChangeRegistrationOptions : publ
 {
 public:
     TextDocumentChangeRegistrationOptions();
-    TextDocumentChangeRegistrationOptions(TextDocumentSyncKind kind);
+    explicit TextDocumentChangeRegistrationOptions(TextDocumentSyncKind kind);
     using JsonObject::JsonObject;
 
     TextDocumentSyncKind syncKind() const
@@ -73,8 +73,8 @@ class LANGUAGESERVERPROTOCOL_EXPORT DidChangeTextDocumentParams : public JsonObj
 {
 public:
     DidChangeTextDocumentParams();
-    DidChangeTextDocumentParams(const VersionedTextDocumentIdentifier &docId,
-                                const QString &text = QString());
+    explicit DidChangeTextDocumentParams(const VersionedTextDocumentIdentifier &docId,
+                                         const QString &text = QString());
     using JsonObject::JsonObject;
 
     VersionedTextDocumentIdentifier textDocument() const
@@ -90,7 +90,7 @@ public:
          */
     public:
         TextDocumentContentChangeEvent() = default;
-        TextDocumentContentChangeEvent(const QString text);
+        explicit TextDocumentContentChangeEvent(const QString &text);
         using JsonObject::JsonObject;
 
         // The range of the document that changed.
@@ -122,7 +122,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DidChangeTextDocumentNotification : public N
         DidChangeTextDocumentParams>
 {
 public:
-    DidChangeTextDocumentNotification(const DidChangeTextDocumentParams &params);
+    explicit DidChangeTextDocumentNotification(const DidChangeTextDocumentParams &params);
     using Notification::Notification;
     constexpr static const char methodName[] = "textDocument/didChange";
 };
@@ -137,8 +137,9 @@ public:
     };
 
     WillSaveTextDocumentParams() : WillSaveTextDocumentParams(TextDocumentIdentifier()) {}
-    WillSaveTextDocumentParams(const TextDocumentIdentifier &document,
-                               const TextDocumentSaveReason &reason = TextDocumentSaveReason::Manual);
+    explicit WillSaveTextDocumentParams(
+        const TextDocumentIdentifier &document,
+        const TextDocumentSaveReason &reason = TextDocumentSaveReason::Manual);
     using JsonObject::JsonObject;
 
     TextDocumentIdentifier textDocument() const
@@ -157,7 +158,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT WillSaveTextDocumentNotification : public No
         WillSaveTextDocumentParams>
 {
 public:
-    WillSaveTextDocumentNotification(const WillSaveTextDocumentParams &params);
+    explicit WillSaveTextDocumentNotification(const WillSaveTextDocumentParams &params);
     using Notification::Notification;
     constexpr static const char methodName[] = "textDocument/willSave";
 };
@@ -166,7 +167,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT WillSaveWaitUntilTextDocumentRequest : publi
         LanguageClientArray<TextEdit>, std::nullptr_t, WillSaveTextDocumentParams>
 {
 public:
-    WillSaveWaitUntilTextDocumentRequest(const WillSaveTextDocumentParams &params);
+    explicit WillSaveWaitUntilTextDocumentRequest(const WillSaveTextDocumentParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "textDocument/willSaveWaitUntil";
 };
@@ -188,7 +189,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DidSaveTextDocumentParams : public JsonObjec
 {
 public:
     DidSaveTextDocumentParams() : DidSaveTextDocumentParams(TextDocumentIdentifier()) {}
-    DidSaveTextDocumentParams(const TextDocumentIdentifier &document);
+    explicit DidSaveTextDocumentParams(const TextDocumentIdentifier &document);
     using JsonObject::JsonObject;
 
     TextDocumentIdentifier textDocument()
@@ -207,7 +208,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DidSaveTextDocumentNotification : public Not
         DidSaveTextDocumentParams>
 {
 public:
-    DidSaveTextDocumentNotification(const DidSaveTextDocumentParams &params);
+    explicit DidSaveTextDocumentNotification(const DidSaveTextDocumentParams &params);
     using Notification::Notification;
     constexpr static const char methodName[] = "textDocument/didSave";
 };
@@ -216,7 +217,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DidCloseTextDocumentParams : public JsonObje
 {
 public:
     DidCloseTextDocumentParams() = default;
-    DidCloseTextDocumentParams(const TextDocumentIdentifier &document);
+    explicit DidCloseTextDocumentParams(const TextDocumentIdentifier &document);
     using JsonObject::JsonObject;
 
     TextDocumentIdentifier textDocument() const
@@ -232,7 +233,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DidCloseTextDocumentNotification : public No
         DidCloseTextDocumentParams>
 {
 public:
-    DidCloseTextDocumentNotification(const DidCloseTextDocumentParams &params);
+    explicit DidCloseTextDocumentNotification(const DidCloseTextDocumentParams &params);
     using Notification::Notification;
     constexpr static const char methodName[] = "textDocument/didClose";
 };
diff --git a/src/libs/languageserverprotocol/workspace.h b/src/libs/languageserverprotocol/workspace.h
index 00669eba01f..2d07f6c0ace 100644
--- a/src/libs/languageserverprotocol/workspace.h
+++ b/src/libs/languageserverprotocol/workspace.h
@@ -80,7 +80,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DidChangeWorkspaceFoldersNotification : publ
         DidChangeWorkspaceFoldersParams>
 {
 public:
-    DidChangeWorkspaceFoldersNotification(const DidChangeWorkspaceFoldersParams &params);
+    explicit DidChangeWorkspaceFoldersNotification(const DidChangeWorkspaceFoldersParams &params);
     constexpr static const char methodName[] = "workspace/didChangeWorkspaceFolders";
     using Notification::Notification;
 };
@@ -100,7 +100,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DidChangeConfigurationNotification : public
         DidChangeConfigurationParams>
 {
 public:
-    DidChangeConfigurationNotification(const DidChangeConfigurationParams &params);
+    explicit DidChangeConfigurationNotification(const DidChangeConfigurationParams &params);
     using Notification::Notification;
     constexpr static const char methodName[] = "workspace/didChangeConfiguration";
 };
@@ -136,7 +136,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT ConfigurationRequest : public Request<
         LanguageClientArray<QJsonValue>, std::nullptr_t, ConfigurationParams>
 {
 public:
-    ConfigurationRequest(const ConfigurationParams &params);
+    explicit ConfigurationRequest(const ConfigurationParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "workspace/configuration";
 };
@@ -178,7 +178,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT DidChangeWatchedFilesNotification : public N
         DidChangeWatchedFilesParams>
 {
 public:
-    DidChangeWatchedFilesNotification(const DidChangeWatchedFilesParams &params);
+    explicit DidChangeWatchedFilesNotification(const DidChangeWatchedFilesParams &params);
     using Notification::Notification;
     constexpr static const char methodName[] = "workspace/didChangeWatchedFiles";
 };
@@ -229,7 +229,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT ExecuteCommandRequest : public Request<
         QJsonValue, std::nullptr_t, ExecuteCommandParams>
 {
 public:
-    ExecuteCommandRequest(const ExecuteCommandParams &params);
+    explicit ExecuteCommandRequest(const ExecuteCommandParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "workspace/executeCommand";
 };
@@ -265,7 +265,7 @@ class LANGUAGESERVERPROTOCOL_EXPORT ApplyWorkspaceEditRequest : public Request<
         ApplyWorkspaceEditResponse, std::nullptr_t, ApplyWorkspaceEditParams>
 {
 public:
-    ApplyWorkspaceEditRequest(const ApplyWorkspaceEditParams &params = ApplyWorkspaceEditParams());
+    explicit ApplyWorkspaceEditRequest(const ApplyWorkspaceEditParams &params);
     using Request::Request;
     constexpr static const char methodName[] = "workspace/applyEdit";
 };
diff --git a/src/plugins/languageclient/client.cpp b/src/plugins/languageclient/client.cpp
index 01bda90a6f4..82dc7e494ec 100644
--- a/src/plugins/languageclient/client.cpp
+++ b/src/plugins/languageclient/client.cpp
@@ -257,8 +257,7 @@ void Client::initialize()
     QTC_ASSERT(m_clientInterface, return);
     QTC_ASSERT(m_state == Uninitialized, return);
     qCDebug(LOGLSPCLIENT) << "initializing language server " << m_displayName;
-    InitializeRequest initRequest;
-    auto params = initRequest.params().value_or(InitializeParams());
+    InitializeParams params;
     params.setCapabilities(generateClientCapabilities());
     params.setInitializationOptions(m_initializationOptions);
     if (m_project) {
@@ -267,7 +266,7 @@ void Client::initialize()
             return WorkSpaceFolder(pro->projectDirectory().toString(), pro->displayName());
         }));
     }
-    initRequest.setParams(params);
+    InitializeRequest initRequest(params);
     initRequest.setResponseCallback([this](const InitializeRequest::Response &initResponse){
         initializeCallback(initResponse);
     });
@@ -535,7 +534,8 @@ void Client::documentContentsChanged(TextEditor::TextDocument *document,
             change.setText(document->textAt(position, charsAdded));
             m_documentsToUpdate[document] << change;
         } else {
-            m_documentsToUpdate[document] = {document->plainText()};
+            m_documentsToUpdate[document] = {
+                DidChangeTextDocumentParams::TextDocumentContentChangeEvent(document->plainText())};
         }
         m_openedDocument[document] = document->plainText();
     }
@@ -590,7 +590,8 @@ void Client::cursorPositionChanged(TextEditor::TextEditorWidget *widget)
     if (runningRequest != m_highlightRequests.end())
         cancelRequest(runningRequest.value());
 
-    DocumentHighlightsRequest request(TextDocumentPositionParams(uri, widget->textCursor()));
+    DocumentHighlightsRequest request(
+        TextDocumentPositionParams(TextDocumentIdentifier(uri), Position(widget->textCursor())));
     request.setResponseCallback(
                 [widget = QPointer<TextEditor::TextEditorWidget>(widget), this, uri]
                 (DocumentHighlightsRequest::Response response)
@@ -641,7 +642,7 @@ void Client::requestCodeActions(const DocumentUri &uri, const QList<Diagnostic>
     CodeActionParams::CodeActionContext context;
     context.setDiagnostics(diagnostics);
     codeActionParams.setContext(context);
-    codeActionParams.setTextDocument(uri);
+    codeActionParams.setTextDocument(TextDocumentIdentifier(uri));
     Position start(0, 0);
     const QTextBlock &lastBlock = doc->document()->lastBlock();
     Position end(lastBlock.blockNumber(), lastBlock.length() - 1);
@@ -768,7 +769,7 @@ void Client::formatFile(const TextEditor::TextDocument *document)
 
     DocumentFormattingParams params;
     const DocumentUri uri = DocumentUri::fromFilePath(filePath);
-    params.setTextDocument(uri);
+    params.setTextDocument(TextDocumentIdentifier(uri));
     params.setOptions(formattingOptions(document->tabSettings()));
     DocumentFormattingRequest request(params);
     request.setResponseCallback(
@@ -799,7 +800,7 @@ void Client::formatRange(const TextEditor::TextDocument *document, const QTextCu
     }
     DocumentRangeFormattingParams params;
     const DocumentUri uri = DocumentUri::fromFilePath(filePath);
-    params.setTextDocument(uri);
+    params.setTextDocument(TextDocumentIdentifier(uri));
     params.setOptions(formattingOptions(document->tabSettings()));
     if (!cursor.hasSelection()) {
         QTextCursor c = cursor;
diff --git a/src/plugins/languageclient/languageclientcompletionassist.cpp b/src/plugins/languageclient/languageclientcompletionassist.cpp
index e354ae4db0c..1d40a38033e 100644
--- a/src/plugins/languageclient/languageclientcompletionassist.cpp
+++ b/src/plugins/languageclient/languageclientcompletionassist.cpp
@@ -354,8 +354,8 @@ IAssistProposal *LanguageClientCompletionAssistProcessor::perform(const AssistIn
     --column; // column is 0 based in the protocol
     params.setPosition({line, column});
     params.setContext(context);
-    params.setTextDocument(
-                DocumentUri::fromFilePath(Utils::FilePath::fromString(interface->fileName())));
+    params.setTextDocument(TextDocumentIdentifier(
+        DocumentUri::fromFilePath(Utils::FilePath::fromString(interface->fileName()))));
     CompletionRequest completionRequest(params);
     completionRequest.setResponseCallback([this](auto response) {
         this->handleCompletionResponse(response);
diff --git a/src/plugins/languageclient/languageclientformatter.cpp b/src/plugins/languageclient/languageclientformatter.cpp
index 300208e8bf9..08586c04ff0 100644
--- a/src/plugins/languageclient/languageclientformatter.cpp
+++ b/src/plugins/languageclient/languageclientformatter.cpp
@@ -89,7 +89,7 @@ QFutureWatcher<Utils::Text::Replacements> *LanguageClientFormatter::format(
     }
     DocumentRangeFormattingParams params;
     const DocumentUri uri = DocumentUri::fromFilePath(filePath);
-    params.setTextDocument(uri);
+    params.setTextDocument(TextDocumentIdentifier(uri));
     params.setOptions(formattingOptions(tabSettings));
     if (!cursor.hasSelection()) {
         QTextCursor c = cursor;
diff --git a/src/plugins/languageclient/languageclientfunctionhint.cpp b/src/plugins/languageclient/languageclientfunctionhint.cpp
index 37635799e88..e43791dbcda 100644
--- a/src/plugins/languageclient/languageclientfunctionhint.cpp
+++ b/src/plugins/languageclient/languageclientfunctionhint.cpp
@@ -86,8 +86,7 @@ IAssistProposal *FunctionHintProcessor::perform(const AssistInterface *interface
     QTextCursor cursor(interface->textDocument());
     cursor.setPosition(m_pos);
     auto uri = DocumentUri::fromFilePath(Utils::FilePath::fromString(interface->fileName()));
-    SignatureHelpRequest request;
-    request.setParams(TextDocumentPositionParams(TextDocumentIdentifier(uri), Position(cursor)));
+    SignatureHelpRequest request((TextDocumentPositionParams(TextDocumentIdentifier(uri), Position(cursor))));
     request.setResponseCallback([this](auto response) { this->handleSignatureResponse(response); });
     m_client->sendContent(request);
     m_currentRequest = request.id();
diff --git a/src/plugins/languageclient/languageclienthoverhandler.cpp b/src/plugins/languageclient/languageclienthoverhandler.cpp
index ec1632e7ffd..b0ff1c28644 100644
--- a/src/plugins/languageclient/languageclienthoverhandler.cpp
+++ b/src/plugins/languageclient/languageclienthoverhandler.cpp
@@ -98,8 +98,7 @@ void HoverHandler::identifyMatch(TextEditor::TextEditorWidget *editorWidget,
     m_report = report;
     QTextCursor cursor = editorWidget->textCursor();
     cursor.setPosition(pos);
-    TextDocumentPositionParams params(uri, Position(cursor));
-    HoverRequest request(params);
+    HoverRequest request((TextDocumentPositionParams(TextDocumentIdentifier(uri), Position(cursor))));
     request.setResponseCallback(
         [this](const HoverRequest::Response &response) { handleResponse(response); });
     m_client->sendContent(request);
diff --git a/src/plugins/languageclient/languageclientquickfix.cpp b/src/plugins/languageclient/languageclientquickfix.cpp
index 6556947dbaf..6eb8359ab08 100644
--- a/src/plugins/languageclient/languageclientquickfix.cpp
+++ b/src/plugins/languageclient/languageclientquickfix.cpp
@@ -113,7 +113,7 @@ IAssistProposal *LanguageClientQuickFixAssistProcessor::perform(const AssistInte
     Range range(cursor);
     params.setRange(range);
     auto uri = DocumentUri::fromFilePath(Utils::FilePath::fromString(interface->fileName()));
-    params.setTextDocument(uri);
+    params.setTextDocument(TextDocumentIdentifier(uri));
     CodeActionParams::CodeActionContext context;
     context.setDiagnostics(m_client->diagnosticsAt(uri, range));
     params.setContext(context);