diff --git a/src/plugins/languageclient/client.cpp b/src/plugins/languageclient/client.cpp
index 9991cb1c88c..f4fa4d6319f 100644
--- a/src/plugins/languageclient/client.cpp
+++ b/src/plugins/languageclient/client.cpp
@@ -111,8 +111,9 @@ Client::~Client()
     using namespace TextEditor;
     // FIXME: instead of replacing the completion provider in the text document store the
     // completion provider as a prioritised list in the text document
-    for (auto it = m_resetAssistProvider.cbegin(); it != m_resetAssistProvider.cend(); ++it)
-        resetAssistProviders(it.key());
+    // temporary container needed since m_resetAssistProvider is changed in resetAssistProviders
+    for (TextDocument *document : m_resetAssistProvider.keys())
+        resetAssistProviders(document);
     const QList<Core::IEditor *> &editors = Core::DocumentModel::editorsForOpenedDocuments();
     for (Core::IEditor *editor : editors) {
         if (auto textEditor = qobject_cast<BaseTextEditor *>(editor)) {
diff --git a/src/plugins/languageclient/diagnosticmanager.cpp b/src/plugins/languageclient/diagnosticmanager.cpp
index 233353a9f71..802ff4a58fd 100644
--- a/src/plugins/languageclient/diagnosticmanager.cpp
+++ b/src/plugins/languageclient/diagnosticmanager.cpp
@@ -130,8 +130,8 @@ void DiagnosticManager::showDiagnostics(const DocumentUri &uri)
 
 void DiagnosticManager::clearDiagnostics()
 {
-    for (auto it = m_diagnostics.cbegin(); it != m_diagnostics.cend(); ++it)
-        removeDiagnostics(it.key());
+    for (const DocumentUri &uri : m_diagnostics.keys())
+        removeDiagnostics(uri);
 }
 
 QList<Diagnostic> DiagnosticManager::diagnosticsAt(const DocumentUri &uri, const Range &range) const
diff --git a/src/plugins/languageclient/languageclientmanager.cpp b/src/plugins/languageclient/languageclientmanager.cpp
index 6c9df52b91b..43213e4de1c 100644
--- a/src/plugins/languageclient/languageclientmanager.cpp
+++ b/src/plugins/languageclient/languageclientmanager.cpp
@@ -387,13 +387,13 @@ void LanguageClientManager::clientFinished(Client *client)
         client->disconnect(this);
         client->log(tr("Unexpectedly finished. Restarting in %1 seconds.").arg(restartTimeoutS));
         QTimer::singleShot(restartTimeoutS * 1000, client, [client]() { startClient(client); });
-        for (auto it = m_clientForDocument.cbegin(); it != m_clientForDocument.cend(); ++it)
-            client->deactivateDocument(it.key());
+        for (TextEditor::TextDocument *document : m_clientForDocument.keys(client))
+            client->deactivateDocument(document);
     } else {
         if (unexpectedFinish && !m_shuttingDown)
             client->log(tr("Unexpectedly finished."));
-        for (auto it = m_clientForDocument.cbegin(); it != m_clientForDocument.cend(); ++it)
-            m_clientForDocument.remove(it.key());
+        for (TextEditor::TextDocument *document : m_clientForDocument.keys(client))
+            m_clientForDocument.remove(document);
         deleteClient(client);
         if (m_shuttingDown && m_clients.isEmpty())
             emit shutdownFinished();