diff --git a/Dockerfile b/Dockerfile
index 6c96f60..5a02118 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -7,6 +7,8 @@ COPY LICENSE \
         requirements.txt \
         /code/
 
+RUN apk add --no-cache bash
+
 RUN pip install -r /code/requirements.txt
 
 ENTRYPOINT ["/code/entrypoint.sh"]
diff --git a/README.md b/README.md
index df04849..e016cf9 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,43 @@ Any warnings or errors will be annotated in the Pull Request.
 uses: codespell-project/actions-codespell@master
 ```
 
+## Possible use for checking a pull request
+```
+# GitHub Action to automate the identification of common misspellings in text files.
+# https://github.com/codespell-project/actions-codespell
+# https://github.com/codespell-project/codespell
+
+name: Codespell
+on: 
+  pull_request_target:
+
+jobs:
+  codespell:
+    name: Check for spelling errors
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Get changed files
+      id: changed-files
+      uses: tj-actions/changed-files@v12.2
+
+    - name: Get the latest dictionary
+      run: |
+        wget https://raw.githubusercontent.com/codespell-project/codespell/master/codespell_lib/data/dictionary.txt
+
+    - name: Get the latest rare dictionary
+      run: |
+        wget https://raw.githubusercontent.com/codespell-project/codespell/master/codespell_lib/data/dictionary_rare.txt    
+
+    - uses: codespell-project/actions-codespell@master
+      with:
+        dictionary: dictionary.txt,dictionary_rare.txt
+        path: ${{ steps.changed-files.outputs.all_changed_files }}
+```
+
+
+
 ### Parameter: check_filenames
 
 If set, check file names for spelling mistakes as well.
@@ -57,6 +94,17 @@ with:
   skip: foo,bar
 ```
 
+### Parameter: dictionary
+
+Comma-separated list of custom dictionaries to use.
+This parameter is optional; by default `codespell` will use the builtin dictionaries.
+
+```
+uses: codespell-project/actions-codespell@master
+with:
+  dictionary: dictionary.txt,dictionary2.txt
+```
+
 ### Parameter: builtin
 
 Comma-separated list of builtin dictionaries to use.
diff --git a/action.yml b/action.yml
index 522d9cf..029d35b 100644
--- a/action.yml
+++ b/action.yml
@@ -18,6 +18,10 @@ inputs:
     description: 'Comma-separated list of files to skip (it accepts globs as well)'
     required: false
     default: './.git'
+  dictionary:
+    description: 'Comma-separated list of custom dictionary files that contains spelling corrections.'
+    required: false
+    default: ''  
   builtin:
     description: 'Comma-separated list of builtin dictionaries to include'
     required: false
diff --git a/entrypoint.sh b/entrypoint.sh
index 0fc188f..177555d 100755
--- a/entrypoint.sh
+++ b/entrypoint.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 # Copy the matcher to the host system; otherwise "add-matcher" can't find it.
 cp /code/codespell-matcher.json /github/workflow/codespell-matcher.json
@@ -28,6 +28,13 @@ echo "Skipping '${INPUT_SKIP}'"
 if [ "x${INPUT_SKIP}" != "x" ]; then
     command_args="${command_args} --skip ${INPUT_SKIP}"
 fi
+echo "Custom dictionary '${INPUT_DICTIONARY}'"
+if [ "x${INPUT_DICTIONARY}" != "x" ]; then
+    IFS=',' read -ra DICTIONARY <<< "${INPUT_DICTIONARY}"
+    for i in "${DICTIONARY[@]}"; do
+        command_args="${command_args} --dictionary $i"
+    done
+fi
 echo "Builtin dictionaries '${INPUT_BUILTIN}'"
 if [ "x${INPUT_BUILTIN}" != "x" ]; then
     command_args="${command_args} --builtin ${INPUT_BUILTIN}"