diff --git a/.github/uitest/uitest.ps1 b/.github/uitest/uitest.ps1
index 1bd3f4c2d5..579c4b8e62 100644
--- a/.github/uitest/uitest.ps1
+++ b/.github/uitest/uitest.ps1
@@ -134,7 +134,13 @@ function Start-Sample {
             }
         }
 		
-		# set environment variable to the application pool
+		# add or update environment variable to the application pool
+		$existingEnvVar = c:\windows\system32\inetsrv\appcmd.exe list config -section:system.applicationHost/applicationPools `
+		     | out-string `
+			 | select-xml -XPath "//add[@name='DefaultAppPool']/environmentVariables/add[@name='GITHUB_TOKEN']"
+		if ($existingEnvVar -ne $null) {
+		    c:\windows\system32\inetsrv\appcmd.exe set config -section:system.applicationHost/applicationPools /-"[name='DefaultAppPool'].environmentVariables.[name='GITHUB_TOKEN']" /commit:apphost
+		}
 		c:\windows\system32\inetsrv\appcmd.exe set config -section:system.applicationHost/applicationPools /+"[name='DefaultAppPool'].environmentVariables.[name='GITHUB_TOKEN',value='$env:GITHUB_TOKEN']" /commit:apphost
     }
 }