diff --git a/CMakeLists.txt b/CMakeLists.txt
index ef9050b4fe2..b2453860d28 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -211,7 +211,8 @@ if (COMPILER_CLANG)
     endif()
 
     # Display absolute paths in error messages. Otherwise KDevelop fails to navigate to correct file and opens a new file instead.
-    set(COMPILER_FLAGS "${COMPILER_FLAGS} -fdiagnostics-absolute-paths")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fdiagnostics-absolute-paths")
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fdiagnostics-absolute-paths")
 
     option(ENABLE_THINLTO "Enable Thin LTO. Only applicable for clang. It's also suppressed when building with tests or sanitizers." ON)