diff --git a/src/plugins/clangcodemodel/clangassistproposalitem.cpp b/src/plugins/clangcodemodel/clangassistproposalitem.cpp
index 012ac9af5e1..75dc40c6710 100644
--- a/src/plugins/clangcodemodel/clangassistproposalitem.cpp
+++ b/src/plugins/clangcodemodel/clangassistproposalitem.cpp
@@ -76,6 +76,7 @@ void ClangAssistProposalItem::apply(TextEditor::TextDocumentManipulatorInterface
     int extraLength = 0;
     int cursorOffset = 0;
     bool setAutoCompleteSkipPos = false;
+    int currentPosition = manipulator.currentPosition();
 
     bool autoParenthesesEnabled = true;
     if (m_completionOperator == T_SIGNAL || m_completionOperator == T_SLOT) {
@@ -124,7 +125,7 @@ void ClangAssistProposalItem::apply(TextEditor::TextDocumentManipulatorInterface
 
                 // If the function doesn't return anything, automatically place the semicolon,
                 // unless we're doing a scope completion (then it might be function definition).
-                const QChar characterAtCursor = manipulator.characterAt(manipulator.currentPosition());
+                const QChar characterAtCursor = manipulator.characterAt(currentPosition);
                 bool endWithSemicolon = m_typedCharacter == QLatin1Char(';')/*
                                                 || (function->returnType()->isVoidType() && m_completionOperator != T_COLON_COLON)*/; //###
                 const QChar semicolon = m_typedCharacter.isNull() ? QLatin1Char(';') : m_typedCharacter;
@@ -181,7 +182,13 @@ void ClangAssistProposalItem::apply(TextEditor::TextDocumentManipulatorInterface
     // Avoid inserting characters that are already there
     QTextCursor cursor = manipulator.textCursorAt(basePosition);
     cursor.movePosition(QTextCursor::EndOfWord);
-    const int currentPosition = cursor.position();
+    const QString textAfterCursor = manipulator.textAt(currentPosition,
+                                                       cursor.position() - currentPosition);
+
+    if (textToBeInserted != textAfterCursor
+            && textToBeInserted.indexOf(textAfterCursor, currentPosition - basePosition) >= 0) {
+        currentPosition = cursor.position();
+    }
 
     for (int i = 0; i < extraCharacters.length(); ++i) {
         const QChar a = extraCharacters.at(i);
diff --git a/src/plugins/cpptools/cppcompletionassist.cpp b/src/plugins/cpptools/cppcompletionassist.cpp
index 0a31d52b848..26b139e6478 100644
--- a/src/plugins/cpptools/cppcompletionassist.cpp
+++ b/src/plugins/cpptools/cppcompletionassist.cpp
@@ -309,28 +309,20 @@ void CppAssistProposalItem::applyContextualContent(TextDocumentManipulatorInterf
             --cursorOffset;
     }
 
-    // Determine the length of characters that should just be kept on the editor, but do
-    // not consider content that ends as an identifier (which could be undesired).
-    const int lineEnd = manipulator.positionAt(EndOfLinePosition);
-    const QString inEditor = manipulator.textAt(manipulator.currentPosition(),
-                                                lineEnd - manipulator.currentPosition());
-    int preserveLength = 0;
-    if (!inEditor.isEmpty()) {
-        preserveLength = toInsert.length() - (manipulator.currentPosition() - basePosition);
-        const int inEditorLength = inEditor.length();
-        while (preserveLength > 0) {
-            if (inEditor.startsWith(toInsert.right(preserveLength))
-                    && (inEditorLength == preserveLength
-                        || !CppTools::isValidIdentifierChar(inEditor.at(preserveLength)))) {
-                break;
-            }
-            --preserveLength;
-        }
+    // Avoid inserting characters that are already there
+    int currentPosition = manipulator.currentPosition();
+    QTextCursor cursor = manipulator.textCursorAt(basePosition);
+    cursor.movePosition(QTextCursor::EndOfWord);
+    const QString textAfterCursor = manipulator.textAt(currentPosition,
+                                                       cursor.position() - currentPosition);
+    if (toInsert != textAfterCursor
+            && toInsert.indexOf(textAfterCursor, currentPosition - basePosition) >= 0) {
+        currentPosition = cursor.position();
     }
 
     for (int i = 0; i < extraChars.length(); ++i) {
         const QChar a = extraChars.at(i);
-        const QChar b = manipulator.characterAt(manipulator.currentPosition() + i + preserveLength);
+        const QChar b = manipulator.characterAt(currentPosition + i);
         if (a == b)
             ++extraLength;
         else
@@ -340,8 +332,9 @@ void CppAssistProposalItem::applyContextualContent(TextDocumentManipulatorInterf
     toInsert += extraChars;
 
     // Insert the remainder of the name
-    const int length = manipulator.currentPosition() - basePosition + preserveLength + extraLength;
+    const int length = currentPosition - basePosition + extraLength;
     manipulator.replace(basePosition, length, toInsert);
+    manipulator.setCursorPosition(basePosition + toInsert.length());
     if (cursorOffset)
         manipulator.setCursorPosition(manipulator.currentPosition() + cursorOffset);
     if (setAutoCompleteSkipPos)
diff --git a/src/plugins/texteditor/codeassist/codeassistant.cpp b/src/plugins/texteditor/codeassist/codeassistant.cpp
index caff27918df..0622f29f10d 100644
--- a/src/plugins/texteditor/codeassist/codeassistant.cpp
+++ b/src/plugins/texteditor/codeassist/codeassistant.cpp
@@ -365,8 +365,21 @@ void CodeAssistantPrivate::handlePrefixExpansion(const QString &newPrefix)
     cursor.setPosition(m_proposal->basePosition());
     cursor.movePosition(QTextCursor::EndOfWord);
 
+    int currentPosition = m_editorWidget->position();
+    const QString textAfterCursor = m_editorWidget->textAt(currentPosition,
+                                                       cursor.position() - currentPosition);
+    if (!textAfterCursor.startsWith(newPrefix)) {
+        if (newPrefix.indexOf(textAfterCursor, currentPosition - m_proposal->basePosition()) >= 0)
+            currentPosition = cursor.position();
+        const QStringRef prefixAddition =
+                newPrefix.midRef(currentPosition - m_proposal->basePosition());
+        // If remaining string starts with the prefix addition
+        if (textAfterCursor.startsWith(prefixAddition))
+            currentPosition += prefixAddition.size();
+    }
+
     m_editorWidget->setCursorPosition(m_proposal->basePosition());
-    m_editorWidget->replace(cursor.position() - m_proposal->basePosition(), newPrefix);
+    m_editorWidget->replace(currentPosition - m_proposal->basePosition(), newPrefix);
     notifyChange();
 }