diff --git a/Tests/MakeClean/CMakeLists.txt b/Tests/MakeClean/CMakeLists.txt
index 5060ae7ee..6f094769a 100644
--- a/Tests/MakeClean/CMakeLists.txt
+++ b/Tests/MakeClean/CMakeLists.txt
@@ -1,5 +1,7 @@
 PROJECT(MakeClean)
 
+SET(CMAKE_C_FLAGS "${CMAKE_ANSI_CFLAGS} ${CMAKE_C_FLAGS}")
+
 # Build the to-clean project.
 TRY_COMPILE(TOCLEAN_BUILT
   ${MakeClean_BINARY_DIR}/ToClean