1 files changed, 2 insertions, 0 deletions
diff --git a/input.h b/input.h
index f7593ce..21f388c 100644
--- a/input.h
+++ b/input.h
@@ -1,6 +1,8 @@
 #ifndef DEF_INPUTH
 #define DEF_INPUTH
 
+#include <stddef.h>
+
 /* simple macro to check a result against an expected value */
 #define CHECK(actual, expected) {\
 	if(actual == expected)\