diff --git a/exec/crypto.c b/exec/crypto.c
index f85f4b92..1564ee8f 100644
--- a/exec/crypto.c
+++ b/exec/crypto.c
@@ -1254,7 +1254,7 @@ static unsigned long rng_nix(unsigned char *buf, unsigned long len,
                              void (*callback)(void))
 {
 	int fd;
-	unsigned long rb;
+	unsigned long rb = 0;
 
 	fd = open ("/dev/urandom", O_RDONLY);