diff --git a/action.yml b/action.yml
index 256515f7..771235c5 100644
--- a/action.yml
+++ b/action.yml
@@ -123,12 +123,8 @@ runs:
         # "Set base sha..."
         if [[ -n "${{ inputs.base_sha }}" ]]; then
           echo "::set-output name=base_sha::${{ inputs.base_sha }}"
-        elif [[ "${{ inputs.since_last_remote_commit }}" == "true" ]]; then
-          if [[ "${{ github.event.before }}" != "0000000000000000000000000000000000000000" ]]; then
+        elif [[ "${{ inputs.since_last_remote_commit }}" == "true" && "${{ github.event.before }}" != "0000000000000000000000000000000000000000" ]]; then
             echo "::set-output name=base_sha::${{ github.event.before }}"
-          else
-            echo "::set-output name=base_sha::${{ github.sha }}"
-          fi
         fi
       id: base-sha
       shell: bash