diff --git a/chat/template.yaml b/chat/template.yaml
index 1d4985eb..24b95aac 100644
--- a/chat/template.yaml
+++ b/chat/template.yaml
@@ -14,6 +14,10 @@ Parameters:
   AzureOpenaiResourceName:
     Type: String
     Description: Azure OpenAI Resource Name
+  EnvironmentPrefix:
+    Type: String
+    Description: Prefix for Index names
+    Default: ""
   OpenSearchEndpoint:
     Type: String
     Description: OpenSearch Endpoint
@@ -198,6 +202,7 @@ Resources:
           AZURE_OPENAI_API_KEY: !Ref AzureOpenaiApiKey
           AZURE_OPENAI_LLM_DEPLOYMENT_ID: !Ref AzureOpenaiLlmDeploymentId
           AZURE_OPENAI_RESOURCE_NAME: !Ref AzureOpenaiResourceName
+          ENV_PREFIX: !Ref EnvironmentPrefix
           OPENSEARCH_ENDPOINT: !Ref OpenSearchEndpoint
           OPENSEARCH_MODEL_ID: !Ref OpenSearchModelId
       Policies:
diff --git a/template.yaml b/template.yaml
index 1180ca1a..91c538fc 100644
--- a/template.yaml
+++ b/template.yaml
@@ -652,6 +652,7 @@ Resources:
         AzureOpenaiApiKey: !Ref AzureOpenaiApiKey
         AzureOpenaiLlmDeploymentId: !Ref AzureOpenaiLlmDeploymentId
         AzureOpenaiResourceName: !Ref AzureOpenaiResourceName
+        EnvironmentPrefix: !Ref EnvironmentPrefix
         OpenSearchEndpoint: !Ref OpenSearchEndpoint
         OpenSearchModelId: !Ref OpenSearchModelId
   chatWebsocketEndpoint: