diff --git a/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp b/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp
index 9a6b1ef6e15..12d70c80002 100644
--- a/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp
+++ b/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp
@@ -331,7 +331,8 @@ void ClangModelManagerSupport::updateLanguageClient(ProjectExplorer::Project *pr
                     continue;
                 if (fallbackClient && fallbackClient->documentOpen(editor->textDocument()))
                     fallbackClient->closeDocument(editor->textDocument());
-                client->openDocument(editor->textDocument());
+                if (!client->documentOpen(editor->textDocument()))
+                    client->openDocument(editor->textDocument());
                 ClangEditorDocumentProcessor::clearTextMarks(editor->textDocument()->filePath());
                 hasDocuments = true;
             }
diff --git a/src/plugins/languageclient/client.cpp b/src/plugins/languageclient/client.cpp
index 4d0abf56708..a2a61f12244 100644
--- a/src/plugins/languageclient/client.cpp
+++ b/src/plugins/languageclient/client.cpp
@@ -354,10 +354,12 @@ void Client::openDocument(TextEditor::TextDocument *document)
     if (!isSupportedDocument(document))
         return;
 
-    m_openedDocument[document] = document->plainText();
-
-    if (m_state != Initialized)
+    if (m_state != Initialized) {
+        m_postponedDocuments << document;
         return;
+    }
+
+    QTC_ASSERT(!m_openedDocument.contains(document), return);
 
     const FilePath &filePath = document->filePath();
     const QString method(DidOpenTextDocumentNotification::methodName);
@@ -377,6 +379,8 @@ void Client::openDocument(TextEditor::TextDocument *document)
                 return;
         }
     }
+
+    m_openedDocument[document] = document->plainText();
     connect(document, &TextDocument::contentsChangedWithPosition, this,
             [this, document](int position, int charsRemoved, int charsAdded) {
         documentContentsChanged(document, position, charsRemoved, charsAdded);
@@ -427,6 +431,7 @@ void Client::closeDocument(TextEditor::TextDocument *document)
     deactivateDocument(document);
     const DocumentUri &uri = DocumentUri::fromFilePath(document->filePath());
     m_highlights[uri].clear();
+    m_postponedDocuments.remove(document);
     if (m_openedDocument.remove(document) != 0) {
         handleDocumentClosed(document);
         if (m_state == Initialized) {
@@ -1452,8 +1457,9 @@ void Client::initializeCallback(const InitializeRequest::Response &initResponse)
         }
     }
 
-    for (auto it = m_openedDocument.cbegin(); it != m_openedDocument.cend(); ++it)
-        openDocument(it.key());
+    for (TextEditor::TextDocument *doc : m_postponedDocuments)
+        openDocument(doc);
+    m_postponedDocuments.clear();
 
     emit initialized(m_serverCapabilities);
 }
diff --git a/src/plugins/languageclient/client.h b/src/plugins/languageclient/client.h
index cd0c01b986d..d046064e30a 100644
--- a/src/plugins/languageclient/client.h
+++ b/src/plugins/languageclient/client.h
@@ -246,6 +246,7 @@ private:
     LanguageFilter m_languagFilter;
     QJsonObject m_initializationOptions;
     QMap<TextEditor::TextDocument *, QString> m_openedDocument;
+    QSet<TextEditor::TextDocument *> m_postponedDocuments;
     QMap<Utils::FilePath, int> m_documentVersions;
     QMap<TextEditor::TextDocument *,
          QList<LanguageServerProtocol::DidChangeTextDocumentParams::TextDocumentContentChangeEvent>>