diff --git a/specification/ai/OpenAI.Assistants/assistants/models.tsp b/specification/ai/OpenAI.Assistants/assistants/models.tsp
index 6f82c711d58d..a7c41fdc8e14 100644
--- a/specification/ai/OpenAI.Assistants/assistants/models.tsp
+++ b/specification/ai/OpenAI.Assistants/assistants/models.tsp
@@ -37,11 +37,11 @@ model Assistant {
   instructions: string | null;
 
   @doc("The collection of tools enabled for the assistant.")
-  tools: ToolDefinition[] = [];
+  tools: ToolDefinition[] = #[];
 
   @encodedName("application/json", "file_ids")
   @doc("A list of attached file IDs, ordered by creation date in ascending order.")
-  fileIds: string[] = [];
+  fileIds: string[] = #[];
 
   ...RequiredNullableMetadata;
 }
@@ -66,11 +66,11 @@ model AssistantCreationOptions {
 
   #suppress "@azure-tools/typespec-azure-core/no-nullable" "OpenAI uses explicit nullability, distinct from optionality"
   @doc("The collection of tools to enable for the new assistant.")
-  tools?: ToolDefinition[] = [];
+  tools?: ToolDefinition[] = #[];
 
   @encodedName("application/json", "file_ids")
   @doc("A list of previously uploaded file IDs to attach to the assistant.")
-  fileIds?: string[] = [];
+  fileIds?: string[] = #[];
 
   ...OptionalNullableMetadata;
 }
@@ -98,11 +98,11 @@ model UpdateAssistantOptions {
   instructions?: string | null;
 
   @doc("The modified collection of tools to enable for the assistant.")
-  tools?: ToolDefinition[] = [];
+  tools?: ToolDefinition[] = #[];
 
   @encodedName("application/json", "file_ids")
   @doc("The modified list of previously uploaded fileIDs to attach to the assistant.")
-  fileIds?: string[] = [];
+  fileIds?: string[] = #[];
 
   ...OptionalNullableMetadata;
 }
diff --git a/specification/ai/OpenAI.Assistants/messages/models.tsp b/specification/ai/OpenAI.Assistants/messages/models.tsp
index 902cfa8f291b..7cfc01dee512 100644
--- a/specification/ai/OpenAI.Assistants/messages/models.tsp
+++ b/specification/ai/OpenAI.Assistants/messages/models.tsp
@@ -18,7 +18,7 @@ model ThreadInitializationMessage {
   A list of file IDs that the assistant should use. Useful for tools like retrieval and code_interpreter that can
   access files.
   """)
-  fileIds?: string[] = [];
+  fileIds?: string[] = #[];
 
   ...OptionalNullableMetadata;
 }
diff --git a/specification/ai/OpenAI.Assistants/runs/models.tsp b/specification/ai/OpenAI.Assistants/runs/models.tsp
index 45d793556490..b7ae41501b09 100644
--- a/specification/ai/OpenAI.Assistants/runs/models.tsp
+++ b/specification/ai/OpenAI.Assistants/runs/models.tsp
@@ -51,11 +51,11 @@ model ThreadRun {
   instructions: string;
 
   @doc("The overridden enabled tools used for this assistant thread run.")
-  tools: ToolDefinition[] = [];
+  tools: ToolDefinition[] = #[];
 
   @encodedName("application/json", "file_ids")
   @doc("A list of attached file IDs, ordered by creation date in ascending order.")
-  fileIds: string[] = [];
+  fileIds: string[] = #[];
 
   @encodedName("application/json", "created_at")
   @encode(DateTimeKnownEncoding.unixTimestamp, int32)
diff --git a/specification/communication/Communication.JobRouter/models.tsp b/specification/communication/Communication.JobRouter/models.tsp
index 8632530e081b..51bc6a213b74 100644
--- a/specification/communication/Communication.JobRouter/models.tsp
+++ b/specification/communication/Communication.JobRouter/models.tsp
@@ -882,7 +882,7 @@ model ScoringRuleOptions {
   batchSize?: int32 = 20;
 
   @doc("List of extra parameters from a job that will be sent as part of the payload to scoring rule. If not set, a job's labels (sent in the payload as `job`) and a job's worker selectors (sent in the payload as `selectors`) are added to the payload of the scoring rule by default. Note: Worker labels are always sent with scoring payload.")
-  scoringParameters?: ScoringRuleParameterSelector[] = [
+  scoringParameters?: ScoringRuleParameterSelector[] = #[
     ScoringRuleParameterSelector.jobLabels,
     ScoringRuleParameterSelector.workerSelectors
   ];
diff --git a/specification/iotoperationsmq/IoTOperationsMQ.Management/models/base.tsp b/specification/iotoperationsmq/IoTOperationsMQ.Management/models/base.tsp
index 7e2df9921356..e08683a47957 100644
--- a/specification/iotoperationsmq/IoTOperationsMQ.Management/models/base.tsp
+++ b/specification/iotoperationsmq/IoTOperationsMQ.Management/models/base.tsp
@@ -118,10 +118,10 @@ model CertManagerIssuerRef {
 @doc("SANs for certificate.")
 model SanForCert {
   @doc("DNS SANs.")
-  dns: string[] = [];
+  dns: string[] = #[];
 
   @doc("IP address SANs.")
-  ip: string[] = [];
+  ip: string[] = #[];
 }
 
 @doc("Mqtt Protocol types")
diff --git a/specification/iotoperationsmq/IoTOperationsMQ.Management/models/mqttbroker.tsp b/specification/iotoperationsmq/IoTOperationsMQ.Management/models/mqttbroker.tsp
index 29be327356b0..3b60a89c2511 100644
--- a/specification/iotoperationsmq/IoTOperationsMQ.Management/models/mqttbroker.tsp
+++ b/specification/iotoperationsmq/IoTOperationsMQ.Management/models/mqttbroker.tsp
@@ -679,7 +679,7 @@ model PrincipalDefinition {
   #suppress "@azure-tools/typespec-azure-resource-manager/arm-no-record" "existing API"
   @doc("A list of key-value pairs that match the attributes of the clients. The attributes are case-sensitive and must match the attributes provided by the clients during authentication.")
   @OpenAPI.extension("x-ms-identifiers", [])
-  attributes?: Record<string>[] = [];
+  attributes?: Record<string>[] = #[];
 
   @doc("A list of client IDs that match the clients. The client IDs are case-sensitive and must match the client IDs provided by the clients during connection.")
   clientids?: string[];