diff --git a/kotlin-sdk-core/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/shared/Protocol.kt b/kotlin-sdk-core/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/shared/Protocol.kt
index 3515b4a..0c82f5e 100644
--- a/kotlin-sdk-core/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/shared/Protocol.kt
+++ b/kotlin-sdk-core/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/shared/Protocol.kt
@@ -436,6 +436,7 @@ public abstract class Protocol(@PublishedApi internal val options: ProtocolOptio
         }
         val handlersToNotify = _responseHandlers.getAndSet(persistentMapOf()).values.toList()
         _progressHandlers.getAndSet(persistentMapOf())
+        recentlyCancelledRequestIds.getAndSet(persistentListOf())
         connection.inFlightRequestJobs.getAndSet(persistentMapOf())
         connection.handlerScope.cancel()
         onClose()