diff --git a/build/linux/copy_dirs.py b/build/linux/copy_dirs.py
index e44128e..3e8ccf6 100644
--- a/build/linux/copy_dirs.py
+++ b/build/linux/copy_dirs.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Copyright 2019 The Hafnium Authors.
 #
@@ -14,7 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-#!/usr/bin/env python
 """Copies all files inside one folder to another, preserving subfolders."""
 
 import argparse