diff --git a/apps/plugins/varvara/devices/file.c b/apps/plugins/varvara/devices/file.c
index e1241296ce..5cc8dbbf67 100644
--- a/apps/plugins/varvara/devices/file.c
+++ b/apps/plugins/varvara/devices/file.c
@@ -49,14 +49,14 @@ file_cleanup(void)
 static Uint16
 get_entry(char *p, Uint16 len, const char *basename, struct dirinfo info)
 {
-	if(len < strlen(basename) + 7)
+	if(len < rb->strlen(basename) + 7)
 		return 0;
 	else if(info.attribute & ATTR_DIRECTORY)
-		return snprintf(p, len, "---- %s\n", basename);
+		return rb->snprintf(p, len, "---- %s\n", basename);
 	else if(info.size < 0x10000)
-		return snprintf(p, len, "%04x %s\n", (Uint16)info.size, basename);
+		return rb->snprintf(p, len, "%04x %s\n", (Uint16)info.size, basename);
 	else
-		return snprintf(p, len, "???? %s\n", basename);
+		return rb->snprintf(p, len, "???? %s\n", basename);
 }
 
 static Uint16
@@ -80,7 +80,7 @@ Uint16
 file_init(const char *filename)
 {
 	file_cleanup();
-	snprintf(current_filename, sizeof(current_filename), "/%s", (filename[0] == '/') ? &filename[1] : filename);
+	rb->snprintf(current_filename, sizeof(current_filename), "/%s", (filename[0] == '/') ? &filename[1] : filename);
 	return 0;
 }
 
@@ -122,7 +122,7 @@ file_stat(void *dest, Uint16 len)
 {
 	DIR *sd;
 	struct dirent *sde;
-	char *basename = strrchr(current_filename, '/');
+	char *basename = rb->strrchr(current_filename, '/');
 	if(basename != current_filename) {
 		*basename = '\0';
 		sd = rb->opendir(current_filename);
@@ -133,7 +133,7 @@ file_stat(void *dest, Uint16 len)
 	}
 	if(sd == NULL) return 0;
 	while((sde = rb->readdir(sd)) != NULL) {
-		if(!strcmp(sde->d_name, basename)) {
+		if(!rb->strcmp(sde->d_name, basename)) {
 			Uint16 ret = get_entry(dest, len, basename, rb->dir_get_info(sd, sde));
 			rb->closedir(sd);
 			return ret;