1 files changed, 1 insertions, 0 deletions
diff --git a/util.h b/util.h
index 076393e..6b61b56 100644
--- a/util.h
+++ b/util.h
@@ -2,6 +2,7 @@
 #define _util_h
 
 #include <stdio.h>
+#include <stdlib.h>
 
 #define CHECK(cond, ...) do { if (!(cond)) { fprintf(stderr, __VA_ARGS__); putchar('\n'); exit(1); } } while(0)
 #define ERROR(...) CHECK(false, __VA_ARGS__)