diff --git a/ccd_defs_check.pl b/ccd_defs_check.pl
deleted file mode 100755
index a4ab094c..00000000
--- a/ccd_defs_check.pl
+++ /dev/null
@@ -1,20 +0,0 @@
-#!/usr/bin/env perl
-
-use strict;
-
-use File::Basename qw( dirname );
-use File::Spec;
-use JSON;
-
-my $dir = dirname($0);
-my $ccd_defs = File::Spec->catfile($dir, 'ccd_defs.json');
-
-open my $fh, $ccd_defs
-    or die "Unable to open $ccd_defs : $!";
-local $/;
-my $json = <$fh>; # Slurp
-close $fh;
-
-decode_json($json);
-print "CCD_DEFS compiles OK\n";
-exit 0;
diff --git a/ccd_defs_check.py b/ccd_defs_check.py
index acb6f7eb..f0a37f8d 100755
--- a/ccd_defs_check.py
+++ b/ccd_defs_check.py
@@ -14,7 +14,12 @@ try:
 	ccd_defs = get_ccd_widths()
 	print "CCD_DEFS compiles OK"
 	print "Definitions in file: {0}".format(len(ccd_defs))
+	exit_code=0
 except IOError as e:
 	print "I/O error with CCD_DEFS file: {0}".format(e.strerror)
+	exit_code=255
 except:
 	print "Error with CCD_DEFS file: {0}".format(sys.exc_info()[1])
+	exit_code=255
+
+sys.exit(exit_code)
diff --git a/hooks/pre-commit b/hooks/pre-commit
index 71d12852..97ffde5c 100755
--- a/hooks/pre-commit
+++ b/hooks/pre-commit
@@ -11,12 +11,14 @@ exec 1>&2
 
 echo "RUNNING PRE-COMMIT"
 
+EXIT_CODE=0
 # Get list of files about to be committed
 if git diff --cached --name-only --diff-filter=ACM | grep 'ccd_defs.json'; then
     echo "We changed ccd_defs.json"
     GIT_ROOT=$(git rev-parse --show-toplevel)
-    perl $GIT_ROOT/ccd_defs_check.pl
+    python $GIT_ROOT/ccd_defs_check.py
+    EXIT_CODE=$(echo $?)
 fi
 
 # non-zero exit fails the commit
-exit 0
+exit $EXIT_CODE