diff --git a/.circleci/config.yml b/.circleci/config.yml
index b55e30c..d0bb24d 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -38,14 +38,7 @@ jobs:
           command: black . --check
       - run:
           name: check word dictionaries are sorted
-          command: |
-            for file in "whitelist.txt" flake8_spellcheck/*.txt;
-            do
-              if [ "$(sort < "$file")" != "$(<"$file")" ]; then
-                echo "$file is not sorted correctly"
-                exit 1
-              fi
-            done
+          command: ./check-sorting.sh
       - run:
           name: yamllint
           command: yamllint .
diff --git a/README.rst b/README.rst
index 59e28ce..627297a 100644
--- a/README.rst
+++ b/README.rst
@@ -62,6 +62,10 @@ adding those word(s) to the appropriate dictionaries:
 * `technical dictionary <flake8_spellcheck/technical.txt>`_
 * `django dictionary <flake8_spellcheck/django.txt>`_
 
+Before you submit a PR, it is recommended to run ``check-sorting.sh`` in the root of this repository,
+to verify that all the dictionary files are still sorted correctly. Sorting is enforced by CI, so
+you'll need to make sure the files are sorted before your PR can be merged.
+
 
 .. |CircleCI| image:: https://circleci.com/gh/MichaelAquilina/flake8-spellcheck.svg?style=svg
    :target: https://circleci.com/gh/MichaelAquilina/flake8-spellcheck
diff --git a/check-sorting.sh b/check-sorting.sh
new file mode 100755
index 0000000..a3150f9
--- /dev/null
+++ b/check-sorting.sh
@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+
+cd "$(dirname "$0")"
+
+# Sorting is locale-dependent, so force sort to use a locale that's always
+# available for consistency.
+export LC_ALL=C
+
+all_sorted="true"
+
+for file in "whitelist.txt" flake8_spellcheck/*.txt; do
+  if [[ "$(sort < "$file")" != "$(<"$file")" ]]; then
+    echo "$file is not sorted correctly" >&2
+    all_sorted="false"
+  fi
+done
+
+if [[ "$all_sorted" == "false" ]]; then
+  exit 1
+fi