diff --git a/Dockerfile b/Dockerfile
index c588dbb..9184847 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM sphinxdoc/sphinx:latest
+FROM sphinxdoc/sphinx:2.4.4
 
 LABEL "maintainer"="Ammar Askar <ammar@ammaraskar.com>"
 
diff --git a/Dockerfile.pdflatex b/Dockerfile.pdflatex
new file mode 100644
index 0000000..ad37a42
--- /dev/null
+++ b/Dockerfile.pdflatex
@@ -0,0 +1,8 @@
+FROM sphinxdoc/sphinx-pdflatex:4.3.2
+
+LABEL "maintainer"="Ammar Askar <ammar@ammaraskar.com>"
+
+ADD entrypoint.py /entrypoint.py
+ADD sphinx_action /sphinx_action
+
+ENTRYPOINT ["/entrypoint.py"]
diff --git a/Dockerfile.sphinx4 b/Dockerfile.sphinx4
new file mode 100644
index 0000000..c665b66
--- /dev/null
+++ b/Dockerfile.sphinx4
@@ -0,0 +1,8 @@
+FROM sphinxdoc/sphinx:4.3.2
+
+LABEL "maintainer"="Ammar Askar <ammar@ammaraskar.com>"
+
+ADD entrypoint.py /entrypoint.py
+ADD sphinx_action /sphinx_action
+
+ENTRYPOINT ["/entrypoint.py"]
diff --git a/action.yml b/action.yml
index 52f24b2..ce825a1 100644
--- a/action.yml
+++ b/action.yml
@@ -32,6 +32,13 @@ inputs:
       A list of additional 'apt' packages to install before running
       sphinx. (Setting this will force-enable 'update' as well.)
     required: false
+  container:
+    description:
+      Run the build in the named container. Must be one of
+      'sphinx4', 'pdflatex', or 'default'.
+    required: false
+    default: 'default'
 runs:
   using: 'docker'
-  image: 'Dockerfile'
+  image: ${{ format('Dockerfile.{0}', inputs.container) }}
+