diff --git a/stream/stream_dvb.c b/stream/stream_dvb.c
index 7cbd690ee6..3fa1b289a0 100644
--- a/stream/stream_dvb.c
+++ b/stream/stream_dvb.c
@@ -123,6 +123,9 @@ static dvb_channels_list *dvb_get_channels(char *filename, int type)
 	FILE *f;
 	char line[CHANNEL_LINE_LEN], *colon;
 
+        if (!filename)
+            return NULL;
+
 	int fields, cnt, pcnt, k;
 	int has8192, has0;
 	dvb_channel_t *ptr, *tmp, chn;
@@ -799,11 +802,11 @@ dvb_config_t *dvb_get_config(void)
                 break;
         }
 
-        if((access(conf_file, F_OK | R_OK) != 0)) {
+        if(conf_file && (access(conf_file, F_OK | R_OK) != 0)) {
             conf_file = talloc_steal(talloc_ctx,
                     mp_find_user_config_file("channels.conf"));
 
-            if((access(conf_file, F_OK | R_OK) != 0)) {
+            if(conf_file && (access(conf_file, F_OK | R_OK) != 0)) {
                 conf_file = talloc_steal(talloc_ctx,
                         mp_find_global_config_file("channels.conf"));
             }
diff --git a/sub/ass_mp.c b/sub/ass_mp.c
index ae069662c6..2312eaeff5 100644
--- a/sub/ass_mp.c
+++ b/sub/ass_mp.c
@@ -262,7 +262,7 @@ void mp_ass_configure_fonts(ASS_Renderer *priv, struct osd_style_opts *opts)
     char *default_font = mp_find_user_config_file("subfont.ttf");
     char *config       = mp_find_config_file("fonts.conf");
 
-    if (!mp_path_exists(default_font)) {
+    if (default_font && !mp_path_exists(default_font)) {
         talloc_free(default_font);
         default_font = NULL;
     }
@@ -334,7 +334,8 @@ ASS_Library *mp_ass_init(struct MPOpts *opts)
     char *path = mp_find_user_config_file("fonts");
     priv = ass_library_init();
     ass_set_message_cb(priv, message_callback, NULL);
-    ass_set_fonts_dir(priv, path);
+    if (path)
+        ass_set_fonts_dir(priv, path);
     ass_set_extract_fonts(priv, opts->use_embedded_fonts);
     talloc_free(path);
     return priv;