diff --git a/Source/kwsys/CMakeLists.txt b/Source/kwsys/CMakeLists.txt
index 68bd8c03d..1f1816ff0 100644
--- a/Source/kwsys/CMakeLists.txt
+++ b/Source/kwsys/CMakeLists.txt
@@ -28,6 +28,10 @@ SET(KWSYS_NO_ANSI_STREAM_HEADERS ${CMAKE_NO_ANSI_STREAM_HEADERS})
 SET(KWSYS_NO_ANSI_STRING_STREAM ${CMAKE_NO_ANSI_STRING_STREAM})
 SET(KWSYS_NO_ANSI_FOR_SCOPE ${CMAKE_NO_ANSI_FOR_SCOPE})
 
+IF(CMAKE_ANSI_CFLAGS)
+  SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${CMAKE_ANSI_CFLAGS}")
+ENDIF(CMAKE_ANSI_CFLAGS)
+
 SET(CLASSES Directory RegularExpression SystemTools)
 SET(H Process)
 SET(HXX Configure)