diff --git a/fish_shell/fish_core.c b/fish_shell/fish_core.c
index 66b9834..5aa9ed2 100644
--- a/fish_shell/fish_core.c
+++ b/fish_shell/fish_core.c
@@ -5,6 +5,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <sys/wait.h>
 #include "fish_core.h"
 
 #define FISH_BUFFER_SIZE 1024