diff --git a/plugins/clang/codecompletion/context.cpp b/plugins/clang/codecompletion/context.cpp
--- a/plugins/clang/codecompletion/context.cpp
+++ b/plugins/clang/codecompletion/context.cpp
@@ -55,6 +55,7 @@
 #include "../duchain/navigationwidget.h"
 #include "../clangsettings/clangsettingsmanager.h"
 
+#include <algorithm>
 #include <functional>
 #include <memory>
 
@@ -105,6 +106,12 @@
   CCP_Unlikely = 80
 };
 
+QStringRef trimLeft(const QStringRef string) {
+    const int position = std::find_if_not(string.begin(), string.end(),
+                            [](QChar c){ return c.isSpace(); }) - string.begin();
+    return string.mid(position);
+}
+
 /**
  * Common base class for Clang code completion items.
  */
@@ -338,7 +345,16 @@
 
     void execute(KTextEditor::View* view, const KTextEditor::Range& word) override
     {
-        view->document()->replaceText(word, m_replacement);
+        KTextEditor::Document* const document = view->document();
+
+        // try and replace leading typed text that match the proposed implementation
+        const QStringRef leading = trimLeft(document->line(word.end().line()).leftRef(word.end().column()));
+        if (!leading.isEmpty() && (m_display.startsWith(leading) || m_replacement.startsWith(leading))) {
+            const KTextEditor::Cursor newStart = {word.end().line(), word.end().column() - leading.size()};
+            document->replaceText({newStart, word.end()}, m_replacement);
+        } else {
+            document->replaceText(word, m_replacement);
+        }
     }
 };
 
diff --git a/plugins/clang/tests/test_codecompletion.cpp b/plugins/clang/tests/test_codecompletion.cpp
--- a/plugins/clang/tests/test_codecompletion.cpp
+++ b/plugins/clang/tests/test_codecompletion.cpp
@@ -1387,6 +1387,24 @@
         << CompletionItems({5, 0}, {"Test", "Test<X, B>::bar(B a)"})
         << "Test<X, B>::bar(B a)"
         << "template <template<class, int> class X, typename B>\nclass Test {\npublic:\nvoid bar(B a);\n};\ntemplate<template<typename, int> class X, typename B> void Test<X, B>::bar(B a)\n{\n}\n";
+
+    QTest::newRow("replace-leading-return-type")
+        << "void foo(int x);\nvoid "
+        << CompletionItems({1, 5}, {"foo(int x)"})
+        << "foo(int x)"
+        << "void foo(int x);\nvoid foo(int x)\n{\n}\n";
+
+    QTest::newRow("replace-leading-function-name")
+        << "void foo(int x);\nfoo"
+        << CompletionItems({1, 3}, {"foo(int x)"})
+        << "foo(int x)"
+        << "void foo(int x);\nvoid foo(int x)\n{\n}\n";
+
+    QTest::newRow("replace-leading-with-class-method")
+        << "class Foo { void bar(int x); };\nvoid "
+        << CompletionItems({1, 5}, {"Foo", "Foo::bar(int x)"})
+        << "Foo::bar(int x)"
+        << "class Foo { void bar(int x); };\nvoid Foo::bar(int x)\n{\n}\n";
 }
 
 void TestCodeCompletion::testIgnoreGccBuiltins()