diff --git a/action.yml b/action.yml
index 0b59265..9c520ed 100644
--- a/action.yml
+++ b/action.yml
@@ -36,6 +36,11 @@ inputs:
 runs:
   using: 'composite'
   steps:
+    - name: 'DEPRECATION WARNING: @master will no longer receive updates and will start to error in the future. Please use version tags like @v1 or commit SHAs in your workflows!'
+      run: |
+        echo "::warning title=DEPRECATION WARNING::@master will no longer receive updates and will start to error in the future. Please use version tags like @v1 or commit SHAs in your workflows!"
+        echo "# :warning: DEPRECATION WARNING :warning:\n\n@master will no longer receive updates and will start to error in the future. Please use version tags like @v1 or commit SHAs in your workflows!" >> $GITHUB_STEP_SUMMARY
+      shell: bash
     - name: Set and export registry flavor preference
       run: echo "JULIA_PKG_SERVER_REGISTRY_PREFERENCE=${JULIA_PKG_SERVER_REGISTRY_PREFERENCE:-eager}" >> ${GITHUB_ENV}
       shell: bash