diff --git a/.github/workflows/pyinstaller_windows.yml b/.github/workflows/pyinstaller_windows.yml
index 3b45f0a1b81..4251f8e8cff 100644
--- a/.github/workflows/pyinstaller_windows.yml
+++ b/.github/workflows/pyinstaller_windows.yml
@@ -73,7 +73,7 @@ jobs:
       - name: PyInstaller Build
         shell: bash -l {0}
         env:
-          CONDA_CUPY_CUDA_PATH: %CUDA_PATH%
+          CONDA_CUPY_CUDA_PATH: ${{env.CUDA_PATH}}
         run: |
           conda activate mantidimaging-dev
           set