diff --git a/src/SourceBuild/Arcade/eng/common/templates/job/source-build-create-tarball.yml b/src/SourceBuild/Arcade/eng/common/templates/job/source-build-create-tarball.yml
index 8e55a40b5..4f993567f 100644
--- a/src/SourceBuild/Arcade/eng/common/templates/job/source-build-create-tarball.yml
+++ b/src/SourceBuild/Arcade/eng/common/templates/job/source-build-create-tarball.yml
@@ -80,9 +80,12 @@ jobs:
     # This prevents allocation of additional agents if the tarball build legs should be skipped.
     # Only build the tarball if the PR touches source-build source.
     - script: |
-        if curl "https://api.github.com/repos/dotnet/installer/pulls/$(System.PullRequest.PullRequestNumber)/files" | grep '"filename": "src/SourceBuild/*'
-        then
-          echo "##vso[task.setvariable variable=_includeTarballBuild;isoutput=true]true"
-        fi
+        # Temporarily disable tarball PR validation until source-build is supported in this channel.
+        echo "##vso[task.setvariable variable=_includeTarballBuild;isoutput=true]false"
+
+        # if curl "https://api.github.com/repos/dotnet/installer/pulls/$(System.PullRequest.PullRequestNumber)/files" | grep '"filename": "src/SourceBuild/*'
+        # then
+        #   echo "##vso[task.setvariable variable=_includeTarballBuild;isoutput=true]true"
+        # fi
       displayName: Tarball Build Check
       name: Tarball_Build_Check