diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index b6b3053..eeed26d 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -16,6 +16,15 @@ jobs:
         java: [8, 8.0.192, 9.0.x, 10, 11.0.x, 11.0.3, 12, 13]
     runs-on: ${{ matrix.os }}
     steps:
+      - uses: actions-ecosystem/action-regex-match@v2
+        id: regex-match
+        if: ${{ github.event_name == 'workflow_dispatch' }}
+        with:
+          text: ${{ github.event.inputs.branch }}
+          regex: '^[a-zA-Z0-9_/\-]+$'
+      - name: Break on invalid branch name
+        run: exit 1
+        if: ${{ github.event_name == 'workflow_dispatch' && steps.regex-match.outputs && steps.regex-match.outputs.match == '' }}
       - uses: actions/checkout@v2
       - uses: actions/setup-java@v1
         with: