Re-add prefix to private function.
diff --git a/lib/zip_file_get_offset.c b/lib/zip_file_get_offset.c
index feb5c6e..28e3ad9 100644
--- a/lib/zip_file_get_offset.c
+++ b/lib/zip_file_get_offset.c
@@ -57,7 +57,7 @@
     offset = za->entry[idx].orig->offset;
 
     if (zip_source_seek(za->src, (zip_int64_t)offset, SEEK_SET) < 0) {
-	zip_error_set_from_source(error, za->src);
+	_zip_error_set_from_source(error, za->src);
 	return 0;
     }