diff --git a/src/plugins/cpptools/compileroptionsbuilder.cpp b/src/plugins/cpptools/compileroptionsbuilder.cpp
index 426a96b5342..c7219465939 100644
--- a/src/plugins/cpptools/compileroptionsbuilder.cpp
+++ b/src/plugins/cpptools/compileroptionsbuilder.cpp
@@ -357,7 +357,7 @@ void CompilerOptionsBuilder::updateFileLanguage(ProjectFile::Kind fileKind)
         else if (ProjectFile::isCxx(fileKind))
             option = "/TP";
         else
-            QTC_ASSERT(false && "File kind not supported by cl driver mode", return;);
+            return; // Do not add anything if we haven't set a file kind yet.
 
         int langOptIndex = m_options.indexOf("/TC");
         if (langOptIndex == -1)