diff --git a/rdesktop.c b/rdesktop.c
index f4609f5..33d1c87 100644
--- a/rdesktop.c
+++ b/rdesktop.c
@@ -1559,7 +1559,7 @@ load_licence(unsigned char **data)
 	if (home == NULL)
 		return -1;
 
-	snprintf((char *) hi, 16, g_hostname);
+	snprintf((char *) hi, 16, "%s", g_hostname);
 	sec_hash_sha1_16(ho, hi, g_static_rdesktop_salt_16);
 	sec_hash_to_string(hash, sizeof(hash), ho, sizeof(ho));
 
@@ -1607,7 +1607,7 @@ save_licence(unsigned char *data, int length)
 		return;
 	}
 
-	snprintf((char *) hi, 16, g_hostname);
+	snprintf((char *) hi, 16, "%s", g_hostname);
 	sec_hash_sha1_16(ho, hi, g_static_rdesktop_salt_16);
 	sec_hash_to_string(hash, sizeof(hash), ho, sizeof(ho));