--- a/src/c-client/auth_md5.c
+++ b/src/c-client/auth_md5.c
@@ -42,17 +42,17 @@ typedef struct {
 
 /* Prototypes */
 
-long auth_md5_valid (void);
-long auth_md5_client (authchallenge_t challenger,authrespond_t responder,
+static long auth_md5_valid (void);
+static long auth_md5_client (authchallenge_t challenger,authrespond_t responder,
 		      char *service,NETMBX *mb,void *stream,
 		      unsigned long *trial,char *user);
-char *auth_md5_server (authresponse_t responder,int argc,char *argv[]);
-char *auth_md5_pwd (char *user);
+static char *auth_md5_server (authresponse_t responder,int argc,char *argv[]);
+static char *auth_md5_pwd (char *user);
 char *apop_login (char *chal,char *user,char *md5,int argc,char *argv[]);
-char *hmac_md5 (char *text,unsigned long tl,char *key,unsigned long kl);
-void md5_init (MD5CONTEXT *ctx);
-void md5_update (MD5CONTEXT *ctx,unsigned char *data,unsigned long len);
-void md5_final (unsigned char *digest,MD5CONTEXT *ctx);
+static char *hmac_md5 (char *text,unsigned long tl,char *key,unsigned long kl);
+static void md5_init (MD5CONTEXT *ctx);
+static void md5_update (MD5CONTEXT *ctx,unsigned char *data,unsigned long len);
+static void md5_final (unsigned char *digest,MD5CONTEXT *ctx);
 static void md5_transform (unsigned long *state,unsigned char *block);
 static void md5_encode (unsigned char *dst,unsigned long *src,int len);
 static void md5_decode (unsigned long *dst,unsigned char *src,int len);
