diff --git a/manimlib/utils/output_directory_getters.py b/manimlib/utils/output_directory_getters.py
index fbf6aefa..3e364271 100644
--- a/manimlib/utils/output_directory_getters.py
+++ b/manimlib/utils/output_directory_getters.py
@@ -78,4 +78,4 @@ def get_sorted_integer_files(directory,
         elif remove_non_integer_files:
             os.remove(full_path)
     indexed_files.sort(key=lambda p: p[0])
-    return map(lambda p: p[1], indexed_files)
+    return list(map(lambda p: p[1], indexed_files))