diff --git a/README.md b/README.md
index ff02229..0b35ac6 100644
--- a/README.md
+++ b/README.md
@@ -8,6 +8,11 @@ The source code directory should have your `.spec` file that PyInstaller generat
 
 If the `src` folder has a `requirements.txt` file, the packages will be installed into the environment before PyInstaller runs.
 
+If you wish to specify a package mirror, this is possibly via the `pypi_url` and/or the `pypi_index_url`, these defaults are:
+
+- `pypi_url` = `https://pypi.python.org/`
+- `pypi_index_url` = `https://pypi.python.org/simple`
+
 ## Example usage
 
 Include this in your `.github/workflows/main.yaml`:
@@ -15,6 +20,7 @@ Include this in your `.github/workflows/main.yaml`:
 ```yaml
 - name: PyInstaller Windows
   uses: JackMcKew/pyinstaller-action-windows@master
+    with: src
 ```
 
 ## Full Example
@@ -52,3 +58,7 @@ jobs:
         name: name-of-artifact
         path: src/dist/windows
 ```
+
+## Sources
+
+A big thank you to all the contributors over at <https://github.com/cdrx/docker-pyinstaller>, this action is just a modified version of their docker container, thank you!
diff --git a/action.yml b/action.yml
index 3dc8a1c..90cd3db 100644
--- a/action.yml
+++ b/action.yml
@@ -9,6 +9,14 @@ inputs:
     description: 'Directory containing source code & .spec file (optional requirements.txt).'
     required: True
     default: src
+  pypi_url:
+    description: 'Specify a custom URL for PYPI'
+    required: False
+    default: https://pypi.python.org/
+  pypi_index_url:
+    description: 'Specify a custom URL for PYPI Index'
+    required: False
+    default: https://pypi.python.org/simple
 outputs:
   output:
     description: 'The output of PyInstaller'
diff --git a/entrypoint.sh b/entrypoint.sh
index 0083b8e..a543a5c 100644
--- a/entrypoint.sh
+++ b/entrypoint.sh
@@ -11,6 +11,10 @@ set -e
 # and don't allow that much flexibility to mount volumes
 SRCDIR=$1
 
+PYPI_URL = $2
+
+PYPI_INDEX_URL = $3
+
 WORKDIR=${SRCDIR:-/src}
 
 #