diff --git a/src/stdlib/stdlib.h b/src/stdlib/stdlib.h
index d8b26eb..725d5d0 100644
--- a/src/stdlib/stdlib.h
+++ b/src/stdlib/stdlib.h
@@ -2,6 +2,7 @@
 
 // Built-in functions
 
+#include <signal.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>