diff --git a/infra/main.bicep b/infra/main.bicep
index 44f3d2ea..fddd01bc 100644
--- a/infra/main.bicep
+++ b/infra/main.bicep
@@ -570,18 +570,22 @@ param createdBy string = contains(deployer(), 'userPrincipalName')
   ? split(deployer().userPrincipalName, '@')[0]
   : deployer().objectId
 
+var existingTags = resourceGroup().tags ?? {}
+
 // ========== Resource Group Tag ========== //
 resource resourceGroupTags 'Microsoft.Resources/tags@2025-04-01' = {
   name: 'default'
   properties: {
-    tags: {
-      ...resourceGroup().tags
-      ...tags
+    tags: union(
+      existingTags,
+      tags,
+      {
       TemplateName: 'Content Processing'
       Type: enablePrivateNetworking ? 'WAF' : 'Non-WAF'
       CreatedBy: createdBy
       DeploymentName: deployment().name
     }
+    )
   }
 }