diff --git a/action.yml b/action.yml
index 18533b9..d09b4a8 100644
--- a/action.yml
+++ b/action.yml
@@ -12,6 +12,9 @@ inputs:
     description: Directory where build artifacts will be placed, relative to workspace
     required: false
     default: ./
+  additional_repositories:
+    description: Additional APT repositories, one per line
+    required: false
 runs:
   using: node12
   main: main.js