diff --git a/cmake/QtHeadersClean.cmake b/cmake/QtHeadersClean.cmake
index a1ebfcef28a..adcf868f5ad 100644
--- a/cmake/QtHeadersClean.cmake
+++ b/cmake/QtHeadersClean.cmake
@@ -237,12 +237,14 @@ function(qt_internal_add_headersclean_target module_target module_headers)
         get_filename_component(input_file_name ${input_path} NAME)
         set(artifact_path "${CMAKE_CURRENT_BINARY_DIR}/header_check/${input_file_name}.o")
 
-        unset(input_base_dir)
-        if(input_path MATCHES "${CMAKE_BINARY_DIR}")
-            set(input_base_dir "${CMAKE_BINARY_DIR}")
-        elseif(input_path MATCHES "${CMAKE_SOURCE_DIR}")
-            set(input_base_dir "${CMAKE_SOURCE_DIR}")
-        endif()
+        set(possible_base_dirs "${CMAKE_BINARY_DIR}" "${CMAKE_SOURCE_DIR}")
+        foreach(dir IN LISTS possible_base_dirs)
+            string(FIND "${input_path}" "${dir}" idx)
+            if(idx EQUAL "0")
+                set(input_base_dir "${dir}")
+                break()
+            endif()
+        endforeach()
 
         if(input_base_dir AND IS_ABSOLUTE "${input_base_dir}" AND IS_ABSOLUTE "${input_path}")
             file(RELATIVE_PATH comment_header_path "${input_base_dir}" "${input_path}")