diff --git a/Source/cmStandardIncludes.h b/Source/cmStandardIncludes.h
index 38a7afac0..5d7e6131a 100644
--- a/Source/cmStandardIncludes.h
+++ b/Source/cmStandardIncludes.h
@@ -76,6 +76,7 @@
 // include the "c" string header
 #include <string.h>
 #include <stdio.h>
+#include <stdlib.h>
 
 #if !defined(_WIN32) && defined(__COMO__)
 // Hack for como strict mode to avoid defining _SVID_SOURCE or _BSD_SOURCE.