diff --git a/packages/microservices/client/client-kafka.ts b/packages/microservices/client/client-kafka.ts
index 7aac2451f5f..ba9ad099a33 100644
--- a/packages/microservices/client/client-kafka.ts
+++ b/packages/microservices/client/client-kafka.ts
@@ -62,7 +62,7 @@ export class ClientKafka extends ClientProxy {
     const consumerOptions =
       this.getOptionsProp(this.options, 'consumer') || ({} as ConsumerConfig);
     const postfixId =
-      this.getOptionsProp(this.options, 'postfixId') || '-client';
+      this.getOptionsProp(this.options, 'postfixId') ?? '-client';
     this.producerOnlyMode =
       this.getOptionsProp(this.options, 'producerOnlyMode') || false;
 
diff --git a/packages/microservices/interfaces/microservice-configuration.interface.ts b/packages/microservices/interfaces/microservice-configuration.interface.ts
index 298115b06a8..f167a414ce7 100644
--- a/packages/microservices/interfaces/microservice-configuration.interface.ts
+++ b/packages/microservices/interfaces/microservice-configuration.interface.ts
@@ -191,6 +191,9 @@ export interface KafkaParserConfig {
 export interface KafkaOptions {
   transport?: Transport.KAFKA;
   options?: {
+    /**
+     * Defaults to `"-server"` on server side and `"-client"` on client side.
+     */
     postfixId?: string;
     client?: KafkaConfig;
     consumer?: ConsumerConfig;
diff --git a/packages/microservices/server/server-kafka.ts b/packages/microservices/server/server-kafka.ts
index 880af956dd1..2a426eaf673 100644
--- a/packages/microservices/server/server-kafka.ts
+++ b/packages/microservices/server/server-kafka.ts
@@ -57,7 +57,7 @@ export class ServerKafka extends Server implements CustomTransportStrategy {
     const consumerOptions =
       this.getOptionsProp(this.options, 'consumer') || ({} as ConsumerConfig);
     const postfixId =
-      this.getOptionsProp(this.options, 'postfixId') || '-server';
+      this.getOptionsProp(this.options, 'postfixId') ?? '-server';
 
     this.brokers = clientOptions.brokers || [KAFKA_DEFAULT_BROKER];