diff --git a/.github/workflows/prometheus.yml b/.github/workflows/prometheus.yml
index 97ea44e6..7aa9e8fd 100644
--- a/.github/workflows/prometheus.yml
+++ b/.github/workflows/prometheus.yml
@@ -65,8 +65,7 @@ jobs:
         uses: actions/checkout@v3
         with:
           repository: "open-telemetry/opentelemetry-cpp"
-          # Fails in unit tests: ref: "v1.15.0"
-          ref: "v1.12.0"
+          ref: "v1.11.0"
           path: "otel_cpp"
           submodules: "recursive"
       - name: run tests
@@ -104,7 +103,7 @@ jobs:
         uses: actions/checkout@v3
         with:
           repository: "open-telemetry/opentelemetry-cpp"
-          ref: "v1.15.0"
+          ref: "v1.11.0"
           path: "otel_cpp"
           submodules: "recursive"
       - name: setup