diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 7c7dbce..284c727 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -61,7 +61,9 @@ jobs:
 
       - name: Install Mercurial
         if: startsWith(matrix.os, 'macos-')
-        run: brew install mercurial
+        run: |
+          brew upgrade
+          brew install mercurial
 
       - name: Run tests with coverage
         if: startsWith(matrix.toxenv, 'py')