diff --git a/ssh-rand-helper.c b/ssh-rand-helper.c
index ebee900..3a29036 100644
--- a/ssh-rand-helper.c
+++ b/ssh-rand-helper.c
@@ -36,6 +36,7 @@
 # include <sys/un.h>
 #endif
 
+#include <errno.h>
 #include <fcntl.h>
 #include <pwd.h>
 #include <signal.h>