diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8cbf14f0..4736a4bc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@
 - Fix issue where foobar2000 WAV files fail with message "ValueError: Incomplete wav chunk." (#379)
 - Build Win32 binaries as well as Win64 (#381)
 - Build official Win32/Win64 binaries on Python 3.8 (the last release to support Windows 7) (#381)
+- Add .mkv/.webm extensions to "Render to Video" dialog (#???)
 
 ## 0.7.0
 
diff --git a/corrscope/gui/__init__.py b/corrscope/gui/__init__.py
index 03a639a5..92035a67 100644
--- a/corrscope/gui/__init__.py
+++ b/corrscope/gui/__init__.py
@@ -525,7 +525,12 @@ def on_action_render(self):
 
         # Name and extension (no folder).
         video_filename = self.get_save_filename(cli.VIDEO_NAME)
-        filters = ["MP4 files (*.mp4)", "All files (*)"]
+        filters = [
+            "MP4 files (*.mp4)",
+            "Matroska files (*.mkv)",
+            "WebM files (*.webm)",
+            "All files (*)",
+        ]
 
         # Points to either `file_dir` or `render_dir`.
         # Folder is obtained from `dir_ref`.