diff --git a/lib/client.js b/lib/client.js
index 6bf4cbd..6a49de2 100644
--- a/lib/client.js
+++ b/lib/client.js
@@ -201,7 +201,7 @@ export default class Client extends EventTarget {
 			if (changed.indexOf("CASEMAPPING") >= 0) {
 				this.setCaseMapping(this.isupport.get("CASEMAPPING"));
 			}
-			if (changed.indexOf("MONITOR") >= 0 && this.isupport.has("MONITOR")) {
+			if (changed.indexOf("MONITOR") >= 0 && this.isupport.has("MONITOR") && this.monitored.size > 0) {
 				let targets = Array.from(this.monitored.keys()).slice(0, this.maxMonitorTargets());
 				this.send({ command: "MONITOR", params: ["+", targets.join(",")] });
 			}