diff --git a/nmltab.py b/nmltab.py
index 5f5eb783..1b844658 100755
--- a/nmltab.py
+++ b/nmltab.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """
 
 General-purpose tools to semantically tabulate, diff and superset Fortran namelist files.
diff --git a/ocean/make_diag_table.py b/ocean/make_diag_table.py
index 2eff913e..ea5d2a9c 100755
--- a/ocean/make_diag_table.py
+++ b/ocean/make_diag_table.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """
 
 Generate MOM5 diag_table file from diag_table_source.yaml
diff --git a/tidy_restarts.py b/tidy_restarts.py
index ebca097d..bd20e9dd 100755
--- a/tidy_restarts.py
+++ b/tidy_restarts.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """
 
 Tidy up restart directories - see argparse description below.