diff --git a/sshdss.c b/sshdss.c
index 7443dafe..74894673 100644
--- a/sshdss.c
+++ b/sshdss.c
@@ -473,7 +473,7 @@ static int dss_openssh_fmtkey(void *key, unsigned char *blob, int len)
     return bloblen;
 }
 
-unsigned char *dss_sign(void *key, char *data, int datalen, int *siglen)
+static unsigned char *dss_sign(void *key, char *data, int datalen, int *siglen)
 {
     /*
      * The basic DSS signing algorithm is: