diff --git a/.github/workflows/python-tests.yml b/.github/workflows/python-tests.yml
index 41a1ff6..dd8c37f 100644
--- a/.github/workflows/python-tests.yml
+++ b/.github/workflows/python-tests.yml
@@ -8,7 +8,7 @@ on:
 
 env:
   # Bucket count for the Flutter suite; the matrix below lists 0..N-1.
-  FLUTTER_SHARDS: 8
+  FLUTTER_SHARDS: 12
 
 jobs:
   test:
@@ -87,7 +87,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        shard: [0, 1, 2, 3, 4, 5, 6, 7]
+        shard: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
     name: flutter test (shard ${{ matrix.shard }})
     steps:
       - uses: actions/checkout@v4