diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9df4ac262..23b18070d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,7 +8,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        smalltalk: [ Pharo64-11, Pharo64-10, Pharo64-9.0, Pharo64-8.0, Pharo64-7.0, GemStone64-3.7.0, GemStone64-3.6.5, GemStone64-3.5.7 ]
+        smalltalk: [ Pharo64-11, Pharo64-10, Pharo64-9.0, Pharo64-8.0, Pharo64-7.0, GemStone64-3.7.0, GemStone64-3.6.6, GemStone64-3.5.7 ]
         experimental: [ false ]
         include:
           - smalltalk: Pharo64-12
@@ -25,6 +25,8 @@ jobs:
       - uses: actions/checkout@v3
       - uses: hpi-swa/setup-smalltalkCI@v1
         with:
+          smalltalkCI-source: 'jbrichau/smalltalkCI'
+          smalltalkCI-branch: 'fix-issue-623'
           smalltalk-image: ${{ matrix.smalltalk }}
       # - name: Setup tmate session
       #   uses: mxschmitt/action-tmate@v3