diff --git a/src/Socket/messages-recv.ts b/src/Socket/messages-recv.ts
index 2afb87ab..de15ad01 100644
--- a/src/Socket/messages-recv.ts
+++ b/src/Socket/messages-recv.ts
@@ -79,7 +79,8 @@ export const makeMessagesRecvSocket = (config: SocketConfig) => {
 		enableCTWARecovery,
 		sessionCleanupConfig
 	} = config
-	const autoCleanCorrupted = (sessionCleanupConfig || DEFAULT_SESSION_CLEANUP_CONFIG).autoCleanCorrupted
+	// Use nullish coalescing to handle partial config properly
+	const autoCleanCorrupted = sessionCleanupConfig?.autoCleanCorrupted ?? DEFAULT_SESSION_CLEANUP_CONFIG.autoCleanCorrupted
 	const sock = makeMessagesSocket(config)
 	const {
 		ev,
diff --git a/src/Socket/socket.ts b/src/Socket/socket.ts
index 5d76e62a..705e2dec 100644
--- a/src/Socket/socket.ts
+++ b/src/Socket/socket.ts
@@ -506,7 +506,11 @@ export const makeSocket = (config: SocketConfig) => {
 	const sessionActivityTracker = makeSessionActivityTracker(keys, logger)
 
 	// Session cleanup manager - removes inactive/orphaned sessions
-	const sessionCleanupConfig = config.sessionCleanupConfig || DEFAULT_SESSION_CLEANUP_CONFIG
+	// Merge user config with defaults to prevent partial overrides from breaking cleanup
+	const sessionCleanupConfig = {
+		...DEFAULT_SESSION_CLEANUP_CONFIG,
+		...(config.sessionCleanupConfig || {})
+	}
 	const sessionCleanup = makeSessionCleanup(
 		keys,
 		signalRepository.lidMapping,
diff --git a/src/Types/Socket.ts b/src/Types/Socket.ts
index 425c20d1..9df4734d 100644
--- a/src/Types/Socket.ts
+++ b/src/Types/Socket.ts
@@ -254,6 +254,6 @@ export type SocketConfig = {
 	 */
 	enableUnifiedSession?: boolean
 
-	/** Session cleanup configuration (optional, uses DEFAULT_SESSION_CLEANUP_CONFIG if not provided) */
-	sessionCleanupConfig?: SessionCleanupConfig
+	/** Session cleanup configuration (optional, partial overrides merged with defaults) */
+	sessionCleanupConfig?: Partial<SessionCleanupConfig>
 }