diff --git a/waku/waku_core/topics/pubsub_topic.nim b/waku/waku_core/topics/pubsub_topic.nim
index 41ea75fb0..b8150de40 100644
--- a/waku/waku_core/topics/pubsub_topic.nim
+++ b/waku/waku_core/topics/pubsub_topic.nim
@@ -41,7 +41,7 @@ const
   StaticShardingPubsubTopicPrefix = Waku2PubsubTopicPrefix & "/rs"
 
 proc parseStaticSharding*(
-    T: type NsPubsubTopic, topic: PubsubTopic | string
+    T: type NsPubsubTopic, topic: PubsubTopic
 ): ParsingResult[NsPubsubTopic] =
   if not topic.startsWith(StaticShardingPubsubTopicPrefix):
     return err(
@@ -72,9 +72,7 @@ proc parseStaticSharding*(
 
   ok(NsPubsubTopic.staticSharding(clusterId, shardId))
 
-proc parse*(
-    T: type NsPubsubTopic, topic: PubsubTopic | string
-): ParsingResult[NsPubsubTopic] =
+proc parse*(T: type NsPubsubTopic, topic: PubsubTopic): ParsingResult[NsPubsubTopic] =
   ## Splits a namespaced topic string into its constituent parts.
   ## The topic string has to be in the format `/<application>/<version>/<topic-name>/<encoding>`
   NsPubsubTopic.parseStaticSharding(topic)
diff --git a/waku/waku_enr/sharding.nim b/waku/waku_enr/sharding.nim
index ce195166f..5ae1aaac8 100644
--- a/waku/waku_enr/sharding.nim
+++ b/waku/waku_enr/sharding.nim
@@ -85,7 +85,7 @@ func contains*(rs: RelayShards, clusterId, shardId: uint16): bool =
 func contains*(rs: RelayShards, topic: NsPubsubTopic): bool =
   return rs.contains(topic.clusterId, topic.shardId)
 
-func contains*(rs: RelayShards, topic: PubsubTopic | string): bool =
+func contains*(rs: RelayShards, topic: PubsubTopic): bool =
   let parseRes = NsPubsubTopic.parse(topic)
   if parseRes.isErr():
     return false
@@ -240,7 +240,7 @@ proc containsShard*(r: Record, clusterId, shardId: uint16): bool =
 proc containsShard*(r: Record, topic: NsPubsubTopic): bool =
   return containsShard(r, topic.clusterId, topic.shardId)
 
-proc containsShard*(r: Record, topic: PubsubTopic | string): bool =
+proc containsShard*(r: Record, topic: PubsubTopic): bool =
   let parseRes = NsPubsubTopic.parse(topic)
   if parseRes.isErr():
     debug "invalid static sharding topic", topic = topic, error = parseRes.error