diff --git a/src/share/yang/modules/utils/check-hashes.sh b/src/share/yang/modules/utils/check-hashes.sh
index 0e6067738a..398d26b921 100755
--- a/src/share/yang/modules/utils/check-hashes.sh
+++ b/src/share/yang/modules/utils/check-hashes.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-# Copyright (C) 2018-2020 Internet Systems Consortium, Inc. ("ISC")
+# Copyright (C) 2018-2021 Internet Systems Consortium, Inc. ("ISC")
 #
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -21,20 +21,34 @@ set -eu
 script_path=$(cd "$(dirname "${0}")" && pwd)
 cd "${script_path}/.."
 
+amend=false
+if test "${1-}" = '-a' || test "${1-}" = '--amend'; then
+    amend=true
+fi
+
+exit_code=0
 for m in *.yang
 do
     hash1=$(yanglint -f yin "${m}" | openssl dgst -sha256 | sed 's/(stdin)= //')
-    h="hashes/$(basename "${m}").hash"
+    h="hashes/$(basename "${m}" .yang).hash"
     if test -f "${h}"
     then
         hash2=$(cat "${h}")
         if test "$hash1" != "$hash2"
         then
+            exit_code=$((exit_code | 1))
             printf 'hash mismatch on %s expected %s in %s\n' "${m}" "${hash1}" "${h}"
-            exit 1
+            if "${amend}"; then
+                printf '%s\n' "${hash1}" > "${h}"
+            fi
         fi
     else
+        exit_code=$((exit_code | 2))
         printf 'missing hash file %s for %s\n' "${h}" "${m}"
-        exit 2
+        if "${amend}"; then
+            printf '%s\n' "${hash1}" > "${h}"
+        fi
     fi
 done
+
+exit "${exit_code}"