diff --git a/tests/check.h b/tests/check.h
index 1a1c120..18e96ab 100644
--- a/tests/check.h
+++ b/tests/check.h
@@ -2,6 +2,7 @@
 #define LITE_TESTS_CHECK_H_
 
 #include <stdarg.h>
+#include <stdlib.h>
 #include <string.h>
 #include <time.h>