diff --git a/tools/devops/automation/scripts/undo_github_merge.ps1 b/tools/devops/automation/scripts/undo_github_merge.ps1
index 32befd5053..af8e54f627 100644
--- a/tools/devops/automation/scripts/undo_github_merge.ps1
+++ b/tools/devops/automation/scripts/undo_github_merge.ps1
@@ -11,8 +11,11 @@ param
 if($IsPr.ToLower() -eq "true") {
     Write-Host "Working on a PR, Undoing the github merge with main."
 
-    git config remote.origin.fetch '+refs/pull/*:refs/remotes/origin/pull/*'
-    git fetch origin
+    $refspec="+refs/pull/$Env:SYSTEM_PULLREQUEST_PULLREQUESTNUMBER/*:refs/remotes/origin/pull/$Env:SYSTEM_PULLREQUEST_PULLREQUESTNUMBER/*"
+
+    Write-Host "Refspec: $refspec"
+
+    git fetch origin "$refspec"
 
     $branch="$SourceBranch".Replace("merge", "head")
     $branch=$branch.Replace("refs", "origin")