diff --git a/.github/actions/bootstrap-poetry/action.yml b/.github/actions/bootstrap-poetry/action.yml
index 9b3dd375166..5a8a8013dd5 100644
--- a/.github/actions/bootstrap-poetry/action.yml
+++ b/.github/actions/bootstrap-poetry/action.yml
@@ -15,6 +15,14 @@ inputs:
     description: pip-compatible installation specification to use for Poetry
     default: 'poetry'
 
+outputs:
+  python-path:
+    description: Path to the installed Python interpreter
+    value: ${{ steps.setup-python.outputs.python-path }}
+  python-version:
+    description: Version of the installed Python interpreter
+    value: ${{ steps.setup-python.outputs.python-version }}
+
 runs:
   using: composite
   steps:
diff --git a/.github/workflows/.tests-matrix.yaml b/.github/workflows/.tests-matrix.yaml
index 6dbf10a3a61..f2d931d47b5 100644
--- a/.github/workflows/.tests-matrix.yaml
+++ b/.github/workflows/.tests-matrix.yaml
@@ -31,6 +31,7 @@ jobs:
       - uses: actions/checkout@v4
 
       - uses: ./.github/actions/bootstrap-poetry
+        id: bootstrap-poetry
         with:
           python-version: ${{ inputs.python-version }}
 
@@ -39,9 +40,9 @@ jobs:
       - uses: actions/cache@v4
         with:
           path: .mypy_cache
-          key: mypy-${{ runner.os }}-py${{ inputs.python-version }}-${{ hashFiles('pyproject.toml', 'poetry.lock') }}
+          key: mypy-${{ runner.os }}-py${{ steps.bootstrap-poetry.outputs.python-version }}-${{ hashFiles('pyproject.toml', 'poetry.lock') }}
           restore-keys: |
-            mypy-${{ runner.os }}-py${{ inputs.python-version }}-
+            mypy-${{ runner.os }}-py${{ steps.bootstrap-poetry.outputs.python-version }}-
             mypy-${{ runner.os }}-
 
       - run: poetry run mypy