diff --git a/TOOLS/matroska.py b/TOOLS/matroska.py
index 5854d63951..cf55db42a4 100755
--- a/TOOLS/matroska.py
+++ b/TOOLS/matroska.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """
 Generate C definitions for parsing Matroska files.
 Can also be used to directly parse Matroska files and display their contents.