diff --git a/packages/protocol/src/common/util.ts b/packages/protocol/src/common/util.ts
index 789bc3cd..b21941c3 100644
--- a/packages/protocol/src/common/util.ts
+++ b/packages/protocol/src/common/util.ts
@@ -236,8 +236,11 @@ export const isPromise = (value: any): value is Promise<any> => {
  * When spawning VS Code tries to preserve the environment but since it's in
  * the browser, it doesn't work.
  */
-export const preserveEnv = (options?: { env?: NodeJS.ProcessEnv } | null): void => {
-	if (options && options.env) {
-		options.env = { ...process.env, ...options.env };
-	}
+export const withEnv = <T extends { env?: NodeJS.ProcessEnv }>(options?: T): T | undefined => {
+	return options && options.env ? {
+		...options,
+		env: {
+			...process.env, ...options.env,
+		},
+	} : options;
 };
diff --git a/packages/protocol/src/node/modules/child_process.ts b/packages/protocol/src/node/modules/child_process.ts
index 0b0c9eb0..5df9a527 100644
--- a/packages/protocol/src/node/modules/child_process.ts
+++ b/packages/protocol/src/node/modules/child_process.ts
@@ -1,6 +1,6 @@
 import * as cp from "child_process";
 import { ServerProxy } from "../../common/proxy";
-import { preserveEnv } from "../../common/util";
+import { withEnv } from "../../common/util";
 import { WritableProxy, ReadableProxy } from "./stream";
 
 // tslint:disable completed-docs
@@ -71,21 +71,15 @@ export class ChildProcessModuleProxy {
 		options?: { encoding?: string | null } & cp.ExecOptions | null,
 		callback?: ((error: cp.ExecException | null, stdin: string | Buffer, stdout: string | Buffer) => void),
 	): Promise<ChildProcessProxies> {
-		preserveEnv(options);
-
-		return this.returnProxies(cp.exec(command, options, callback));
+		return this.returnProxies(cp.exec(command, options && withEnv(options), callback));
 	}
 
 	public async fork(modulePath: string, args?: string[], options?: cp.ForkOptions): Promise<ChildProcessProxies> {
-		preserveEnv(options);
-
-		return this.returnProxies((this.forkProvider || cp.fork)(modulePath, args, options));
+		return this.returnProxies((this.forkProvider || cp.fork)(modulePath, args, withEnv(options)));
 	}
 
 	public async spawn(command: string, args?: string[], options?: cp.SpawnOptions): Promise<ChildProcessProxies> {
-		preserveEnv(options);
-
-		return this.returnProxies(cp.spawn(command, args, options));
+		return this.returnProxies(cp.spawn(command, args, withEnv(options)));
 	}
 
 	private returnProxies(process: cp.ChildProcess): ChildProcessProxies {
diff --git a/packages/protocol/src/node/modules/node-pty.ts b/packages/protocol/src/node/modules/node-pty.ts
index c5f2581c..c6786d41 100644
--- a/packages/protocol/src/node/modules/node-pty.ts
+++ b/packages/protocol/src/node/modules/node-pty.ts
@@ -2,7 +2,7 @@
 import { EventEmitter } from "events";
 import * as pty from "node-pty";
 import { ServerProxy } from "../../common/proxy";
-import { preserveEnv } from "../../common/util";
+import { withEnv } from "../../common/util";
 
 // tslint:disable completed-docs
 
@@ -66,8 +66,6 @@ export class NodePtyProcessProxy extends ServerProxy {
  */
 export class NodePtyModuleProxy {
 	public async spawn(file: string, args: string[] | string, options: pty.IPtyForkOptions): Promise<NodePtyProcessProxy> {
-		preserveEnv(options);
-
-		return new NodePtyProcessProxy(require("node-pty").spawn(file, args, options));
+		return new NodePtyProcessProxy(require("node-pty").spawn(file, args, withEnv(options)));
 	}
 }
diff --git a/packages/server/src/cli.ts b/packages/server/src/cli.ts
index 13bbd7bc..54a98b96 100644
--- a/packages/server/src/cli.ts
+++ b/packages/server/src/cli.ts
@@ -1,6 +1,6 @@
 import { field, logger } from "@coder/logger";
 import { ServerMessage, SharedProcessActive } from "@coder/protocol/src/proto";
-import { preserveEnv } from "@coder/protocol";
+import { withEnv } from "@coder/protocol";
 import { ChildProcess, fork, ForkOptions } from "child_process";
 import { randomFillSync } from "crypto";
 import * as fs from "fs";
@@ -175,21 +175,12 @@ const bold = (text: string | number): string | number => {
 	}
 
 	if (options.installExtension) {
-
-		let forkOptions = {
-			env: {
-				VSCODE_ALLOW_IO: "true"
-			}
-		}
-
-		preserveEnv(forkOptions);
-
 		const fork = forkModule("vs/code/node/cli", [
 			"--user-data-dir", dataDir,
 			"--builtin-extensions-dir", builtInExtensionsDir,
 			"--extensions-dir", extensionsDir,
 			"--install-extension", options.installExtension,
-		], forkOptions, dataDir);
+		], withEnv({ env: { VSCODE_ALLOW_IO: "true" } }), dataDir);
 
 		fork.stdout.on("data", (d: Buffer) => d.toString().split("\n").forEach((l) => logger.info(l)));
 		fork.stderr.on("data", (d: Buffer) => d.toString().split("\n").forEach((l) => logger.error(l)));
diff --git a/packages/server/src/vscode/sharedProcess.ts b/packages/server/src/vscode/sharedProcess.ts
index 5c10318c..1348f1d8 100644
--- a/packages/server/src/vscode/sharedProcess.ts
+++ b/packages/server/src/vscode/sharedProcess.ts
@@ -7,7 +7,7 @@ import { ParsedArgs } from "vs/platform/environment/common/environment";
 import { Emitter } from "@coder/events/src";
 import { retry } from "@coder/ide/src/retry";
 import { logger, field, Level } from "@coder/logger";
-import { preserveEnv } from "@coder/protocol";
+import { withEnv } from "@coder/protocol";
 
 export enum SharedProcessState {
 	Stopped,
@@ -89,15 +89,10 @@ export class SharedProcess {
 			this.activeProcess.kill();
 		}
 
-		let forkOptions = {
-			env: {
-				VSCODE_ALLOW_IO: "true"
-			}
-		}
-
-		preserveEnv(forkOptions);
-
-		const activeProcess = forkModule("vs/code/electron-browser/sharedProcess/sharedProcessMain", [], forkOptions, this.userDataDir);
+		const activeProcess = forkModule(
+			"vs/code/electron-browser/sharedProcess/sharedProcessMain", [],
+			withEnv({ env: { VSCODE_ALLOW_IO: "true" } }), this.userDataDir,
+		);
 		this.activeProcess = activeProcess;
 
 		await new Promise((resolve, reject): void => {