diff --git a/.github/workflows/Build_mR-NB.yml b/.github/workflows/Build_mR-NB.yml
index a1debab1b..d69dac1a1 100644
--- a/.github/workflows/Build_mR-NB.yml
+++ b/.github/workflows/Build_mR-NB.yml
@@ -41,7 +41,8 @@ jobs:
       
           Write-Host "Transforming T4 template"
           t4 $ttFile -P platformType=${{ matrix.platform }}
-
+        env:
+          PLATFORM: '${{ matrix.platform }}'