diff --git a/.github/workflows/create-codespaces-prebuild.yml b/.github/workflows/create-codespaces-prebuild.yml
index 341254eb793479..cbae714eb4003c 100644
--- a/.github/workflows/create-codespaces-prebuild.yml
+++ b/.github/workflows/create-codespaces-prebuild.yml
@@ -6,6 +6,8 @@ on:
   workflow_dispatch:
 jobs:
   createPrebuild:
+    # Only run in the main repository since it will fail in forks
+    if: github.repository == 'dotnet/runtime'
     permissions:
       contents: write
     runs-on: ubuntu-latest