diff --git a/lib/process-manager.js b/lib/process-manager.js
index a608a1fd04..1665f38430 100644
--- a/lib/process-manager.js
+++ b/lib/process-manager.js
@@ -28,10 +28,12 @@ class SubprocessStream extends Streams.ObjectReadWriteStream {
 		this.process.send(`${taskId}\nNEW`);
 	}
 	_write(/** @type {string} */ message) {
+		if (!process.connected) return;
 		this.process.send(`${this.taskId}\nWRITE\n${message}`);
 		// responses are handled in ProcessWrapper
 	}
 	_destroy() {
+		if (!process.connected) return;
 		this.process.send(`${this.taskId}\nDESTROY`);
 	}
 }
@@ -67,6 +69,9 @@ class QueryProcessWrapper {
 
 			if (this.resolveRelease && !this.load) this.destroy();
 		});
+		this.process.on('disconnect', () => {
+			this.destroy();
+		});
 	}
 
 	get load() {
diff --git a/room-battle.js b/room-battle.js
index f4d0988f2c..949d334ba2 100644
--- a/room-battle.js
+++ b/room-battle.js
@@ -576,6 +576,13 @@ class Battle {
 		while ((next = await this.stream.read())) {
 			this.receive(next.split('\n'));
 		}
+		if (!this.ended) {
+			this.room.add(`|bigerror|The simulator process has crashed. We've been notified and will fix this ASAP.`);
+			Monitor.crashlog(new Error(`Process disconnected`), `A battle`);
+			this.started = true;
+			this.ended = true;
+			this.checkActive();
+		}
 	}
 	receive(/** @type {string[]} */ lines) {
 		switch (lines[0]) {
@@ -960,6 +967,7 @@ class Battle {
 	}
 
 	destroy() {
+		this.ended = true;
 		this.stream.destroy();
 		if (this.active) {
 			Rooms.global.battleCount += -1;