diff --git a/break.c b/break.c
index 38828a3..3c39b67 100644
--- a/break.c
+++ b/break.c
@@ -2,6 +2,7 @@
 #include <stdio.h>
 #include <sys/mman.h> // mmap and friends
 #include <unistd.h>
+#include <stdbool.h>
 
 int main(void) {
     /*