diff --git a/lib/process-manager.ts b/lib/process-manager.ts
index b28d789086d9..3c31f2faa123 100644
--- a/lib/process-manager.ts
+++ b/lib/process-manager.ts
@@ -23,45 +23,46 @@ export const processManagers: ProcessManager[] = [];
 export const disabled = false;
 
 class SubprocessStream extends Streams.ObjectReadWriteStream<string> {
-	process: ChildProcess;
+	process: StreamProcessWrapper;
 	taskId: number;
-	constructor(process: ChildProcess, taskId: number) {
+	constructor(process: StreamProcessWrapper, taskId: number) {
 		super();
 		this.process = process;
 		this.taskId = taskId;
-		this.process.send(`${taskId}\nNEW`);
+		this.process.process.send(`${taskId}\nNEW`);
 	}
 	_write(message: string) {
-		if (!this.process.connected) {
+		if (!this.process.process.connected) {
 			this.pushError(new Error(`Process disconnected (possibly crashed?)`));
 			return;
 		}
-		this.process.send(`${this.taskId}\nWRITE\n${message}`);
+		this.process.process.send(`${this.taskId}\nWRITE\n${message}`);
 		// responses are handled in ProcessWrapper
 	}
 	_writeEnd() {
-		this.process.send(`${this.taskId}\nWRITEEND`);
+		this.process.process.send(`${this.taskId}\nWRITEEND`);
 	}
 	_destroy() {
-		if (!this.process.connected) return;
-		this.process.send(`${this.taskId}\nDESTROY`);
+		if (!this.process.process.connected) return;
+		this.process.process.send(`${this.taskId}\nDESTROY`);
+		this.process.deleteStream(this.taskId);
+		this.process = null!;
 	}
 }
 
 class RawSubprocessStream extends Streams.ObjectReadWriteStream<string> {
-	process: ChildProcess & {process: undefined} | Worker;
-	constructor(process: ChildProcess | Worker) {
+	process: RawProcessWrapper;
+	constructor(process: RawProcessWrapper) {
 		super();
-		this.process = process as any;
+		this.process = process;
 	}
 	_write(message: string) {
-		const isConnected = (this.process.process ? this.process.process : this.process).connected;
-		if (!isConnected) {
+		if (!this.process.getProcess().connected) {
 			// no error because the crash handler should already have shown an error, and
 			// sometimes harmless messages are sent during cleanup
 			return;
 		}
-		this.process.send(message);
+		this.process.process.send(message);
 		// responses are handled in ProcessWrapper
 	}
 }
@@ -194,7 +195,7 @@ export class StreamProcessWrapper implements ProcessWrapper {
 
 			const taskId = parseInt(message.slice(0, nlLoc));
 			const stream = this.activeStreams.get(taskId);
-			if (!stream) throw new Error(`Invalid taskId ${message.slice(0, nlLoc)}`);
+			if (!stream) return; // stream already destroyed
 
 			message = message.slice(nlLoc + 1);
 			nlLoc = message.indexOf('\n');
@@ -235,7 +236,7 @@ export class StreamProcessWrapper implements ProcessWrapper {
 	createStream(): SubprocessStream {
 		this.taskId++;
 		const taskId = this.taskId;
-		const stream = new SubprocessStream(this.process, taskId);
+		const stream = new SubprocessStream(this, taskId);
 		this.activeStreams.set(taskId, stream);
 		return stream;
 	}
@@ -316,7 +317,7 @@ export class RawProcessWrapper implements ProcessWrapper, StreamWorker {
 			this.stream.push(message);
 		});
 
-		this.stream = new RawSubprocessStream(this.process);
+		this.stream = new RawSubprocessStream(this);
 	}
 
 	getProcess() {
@@ -432,9 +433,9 @@ export abstract class ProcessManager {
 		this.releasingProcesses = this.releasingProcesses.concat(processes);
 		return Promise.all(released);
 	}
-	spawn(count = 1) {
+	spawn(count = 1, force?: boolean) {
 		if (!this.isParentProcess) return;
-		if (disabled) return;
+		if (disabled && !force) return;
 		while (this.processes.length < count) {
 			const process = this.createProcess();
 			process.process.on('disconnect', () => this.releaseCrashed(process));
diff --git a/sim/battle-stream.ts b/sim/battle-stream.ts
index 3f9c825405e4..01d394b3e447 100644
--- a/sim/battle-stream.ts
+++ b/sim/battle-stream.ts
@@ -117,9 +117,9 @@ export class BattleStream extends Streams.ObjectReadWriteStream<string> {
 		}
 	}
 
-	_end() {
-		// this is in theory synchronous...
-		this.pushEnd();
+	_writeEnd() {
+		// if battle already ended, we don't need to pushEnd.
+		if (!this.atEOF) this.pushEnd();
 		this._destroy();
 	}
 
@@ -274,7 +274,7 @@ export class BattleTextStream extends Streams.ReadWriteStream {
 		}
 	}
 
-	_end() {
+	_writeEnd() {
 		return this.battleStream.writeEnd();
 	}
 }
diff --git a/sim/tools/runner.ts b/sim/tools/runner.ts
index e5a13dcbbfdd..893dff73e1d9 100644
--- a/sim/tools/runner.ts
+++ b/sim/tools/runner.ts
@@ -175,11 +175,11 @@ class DualStream {
 		this.compare();
 	}
 
-	end() {
-		// We need to compare first because _end() destroys the battle object.
+	writeEnd() {
+		// We need to compare first because _writeEnd() destroys the battle object.
 		this.compare(true);
-		this.control._end();
-		this.test._end();
+		this.control._writeEnd();
+		this.test._writeEnd();
 	}
 
 	compare(end?: boolean) {
diff --git a/test/server/room-battle.js b/test/server/room-battle.js
index 5214d7ec535c..44ed4a74d03c 100644
--- a/test/server/room-battle.js
+++ b/test/server/room-battle.js
@@ -34,4 +34,44 @@ describe('Simulator abstraction layer features', function () {
 			});
 		});
 	});
+
+	describe('BattleStream', function () {
+		it('should work (slow)', async function () {
+			Config.simulatorprocesses = 1;
+			const PM = require('../../.server-dist/room-battle').PM;
+			assert.equal(PM.processes.length, 0);
+			PM.spawn(1, true);
+			assert.equal(PM.processes[0].load, 0);
+
+			const stream = PM.createStream();
+			assert.equal(PM.processes[0].load, 1);
+			stream.write(
+				'>version a2393dfd2a2da5594148bf99eea514e72b136c2c\n' +
+				'>start {"formatid":"gen8randombattle","seed":[9619,36790,28450,62465],"rated":"Rated battle"}\n' +
+				'>player p1 {"name":"p1","avatar":"ethan","team":"","rating":1507,"seed":[59512,58581,51338,7861]}\n' +
+				'>player p2 {"name":"p2","avatar":"dawn","team":"","rating":1447,"seed":[33758,53485,62378,29757]}\n' +
+				'>p1 move 1\n' +
+				'>p2 move 1\n'
+			);
+			assert((await stream.read()).includes('|move|'));
+			stream.destroy();
+			assert.equal(PM.processes[0].load, 0);
+
+			const stream2 = PM.createStream();
+			assert.equal(PM.processes[0].load, 1);
+			stream2.write(
+				'>version a2393dfd2a2da5594148bf99eea514e72b136c2c\n' +
+				'>start {"formatid":"gen8randombattle","seed":[9619,36790,28450,62465],"rated":"Rated battle"}\n' +
+				'>player p1 {"name":"p1","avatar":"ethan","team":"","rating":1507,"seed":[59512,58581,51338,7861]}\n' +
+				'>player p2 {"name":"p2","avatar":"dawn","team":"","rating":1447,"seed":[33758,53485,62378,29757]}\n' +
+				'>p1 move 1\n' +
+				'>p2 move 1\n'
+			);
+			assert((await stream2.read()).includes('|move|'));
+			stream2.writeEnd();
+			await stream2.readAll();
+			assert.equal(PM.processes[0].load, 0);
+			PM.unspawn();
+		});
+	});
 });