diff --git a/cmake/QtProcessConfigureArgs.cmake b/cmake/QtProcessConfigureArgs.cmake
index 6871d560ed7..e46419ce19f 100644
--- a/cmake/QtProcessConfigureArgs.cmake
+++ b/cmake/QtProcessConfigureArgs.cmake
@@ -559,7 +559,7 @@ function(guess_compiler_from_mkspec)
     if(NOT auto_detect_compiler)
         return()
     endif()
-    string(REGEX MATCH "(^|;)-DQT_QMAKE_TARGET_MKSPEC=\([^;]+\)" m ${cmake_args})
+    string(REGEX MATCH "(^|;)-DQT_QMAKE_TARGET_MKSPEC=\([^;]+\)" m "${cmake_args}")
     set(mkspec ${CMAKE_MATCH_2})
     if(mkspec MATCHES "-clang(-|$)")
         push("-DCMAKE_C_COMPILER=clang")