diff --git a/server-fn.c b/server-fn.c
index 6ab7fa485..29802a60f 100644
--- a/server-fn.c
+++ b/server-fn.c
@@ -20,6 +20,7 @@
 #include <sys/wait.h>
 #include <sys/uio.h>
 
+#include <signal.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>