diff --git a/mcp/src/main/java/io/modelcontextprotocol/client/transport/StdioClientTransport.java b/mcp/src/main/java/io/modelcontextprotocol/client/transport/StdioClientTransport.java
index 246ff11..8545348 100644
--- a/mcp/src/main/java/io/modelcontextprotocol/client/transport/StdioClientTransport.java
+++ b/mcp/src/main/java/io/modelcontextprotocol/client/transport/StdioClientTransport.java
@@ -346,14 +346,14 @@ public class StdioClientTransport implements McpClientTransport {
 		return Mono.fromRunnable(() -> {
 			isClosing = true;
 			logger.debug("Initiating graceful shutdown");
-		}).then(Mono.defer(() -> {
+		}).then(Mono.<Void>defer(() -> {
 			// First complete all sinks to stop accepting new messages
 			inboundSink.tryEmitComplete();
 			outboundSink.tryEmitComplete();
 			errorSink.tryEmitComplete();
 
 			// Give a short time for any pending messages to be processed
-			return Mono.delay(Duration.ofMillis(100));
+			return Mono.delay(Duration.ofMillis(100)).then();
 		})).then(Mono.defer(() -> {
 			logger.debug("Sending TERM to process");
 			if (this.process != null) {