diff --git a/integration/error-sanitization-test.ts b/integration/error-sanitization-test.ts
index 7c3cd1bc0a8..a26e407275e 100644
--- a/integration/error-sanitization-test.ts
+++ b/integration/error-sanitization-test.ts
@@ -140,9 +140,12 @@ test.describe("Error Sanitization", () => {
 
   test.describe("serverMode=production", () => {
     test.beforeAll(async () => {
-      fixture = await createFixture({
-        files: routeFiles,
-      });
+      fixture = await createFixture(
+        {
+          files: routeFiles,
+        },
+        ServerMode.Production
+      );
     });
 
     test("renders document without errors", async () => {
@@ -183,7 +186,7 @@ test.describe("Error Sanitization", () => {
       expect(html).toMatch("Defer Route");
       expect(html).toMatch("RESOLVED");
       expect(html).not.toMatch("MESSAGE:");
-      expect(html).not.toMatch(/stack/i);
+      expect(html).not.toMatch(/"stack":/i);
     });
 
     test("sanitizes defer errors in document requests", async () => {
@@ -191,9 +194,8 @@ test.describe("Error Sanitization", () => {
       let html = await response.text();
       expect(html).toMatch("Defer Error");
       expect(html).not.toMatch("RESOLVED");
-      // TODO: is this expected or should we get "Unexpected Server Error" here?
-      expect(html).toMatch('{"message":"REJECTED"}');
-      expect(html).not.toMatch(/stack/i);
+      expect(html).toMatch('{"message":"Unexpected Server Error"}');
+      expect(html).not.toMatch(/"stack":/i);
     });
 
     test("returns data without errors", async () => {
@@ -291,7 +293,7 @@ test.describe("Error Sanitization", () => {
       expect(html).toMatch("Defer Route");
       expect(html).toMatch("RESOLVED");
       expect(html).not.toMatch("MESSAGE:");
-      expect(html).not.toMatch(/stack/i);
+      expect(html).not.toMatch(/"stack":/i);
     });
 
     test("does not sanitize defer errors in document requests", async () => {
@@ -299,9 +301,8 @@ test.describe("Error Sanitization", () => {
       let html = await response.text();
       expect(html).toMatch("Defer Error");
       expect(html).not.toMatch("RESOLVED");
-      expect(html).toMatch('{"message":"REJECTED"}');
-      // TODO: I think we should be getting the stack here too?
-      expect(html).toMatch(/stack/i);
+      // TODO: Is our ServerMode.Development not making it into the build somehow?
+      expect(html).toMatch('{"message":"REJECTED","stack":"}');
     });
 
     test("returns data without errors", async () => {
diff --git a/integration/helpers/create-fixture.ts b/integration/helpers/create-fixture.ts
index d5828db1f59..ff390ea226f 100644
--- a/integration/helpers/create-fixture.ts
+++ b/integration/helpers/create-fixture.ts
@@ -35,7 +35,7 @@ export function json(value: JsonObject) {
 }
 
 export async function createFixture(init: FixtureInit, mode?: ServerMode) {
-  let projectDir = await createFixtureProject(init);
+  let projectDir = await createFixtureProject(init, mode);
   let buildPath = path.resolve(projectDir, "build");
   let app: ServerBuild = await import(buildPath);
   let handler = createRequestHandler(app, mode || ServerMode.Production);
@@ -141,7 +141,8 @@ export async function createAppFixture(fixture: Fixture, mode?: ServerMode) {
 ////////////////////////////////////////////////////////////////////////////////
 
 export async function createFixtureProject(
-  init: FixtureInit = {}
+  init: FixtureInit = {},
+  mode?: ServerMode
 ): Promise<string> {
   let template = init.template ?? "node-template";
   let integrationTemplateDir = path.join(__dirname, template);
@@ -193,17 +194,30 @@ export async function createFixtureProject(
   }
 
   await writeTestFiles(init, projectDir);
-  build(projectDir, init.buildStdio, init.sourcemap);
+  build(projectDir, init.buildStdio, init.sourcemap, mode);
 
   return projectDir;
 }
 
-function build(projectDir: string, buildStdio?: Writable, sourcemap?: boolean) {
+function build(
+  projectDir: string,
+  buildStdio?: Writable,
+  sourcemap?: boolean,
+  mode?: ServerMode
+) {
   let buildArgs = ["node_modules/@remix-run/dev/dist/cli.js", "build"];
   if (sourcemap) {
     buildArgs.push("--sourcemap");
   }
-  let buildSpawn = spawnSync("node", buildArgs, { cwd: projectDir });
+
+  console.log("Building with NODE_ENV =", mode || ServerMode.Production);
+  let buildSpawn = spawnSync("node", buildArgs, {
+    cwd: projectDir,
+    env: {
+      ...process.env,
+      NODE_ENV: mode || ServerMode.Production,
+    },
+  });
 
   // These logs are helpful for debugging. Remove comments if needed.
   // console.log("spawning @remix-run/dev/cli.js `build`:\n");
diff --git a/packages/remix-react/components.tsx b/packages/remix-react/components.tsx
index 092d4e52e6f..f854ff5aa72 100644
--- a/packages/remix-react/components.tsx
+++ b/packages/remix-react/components.tsx
@@ -815,8 +815,9 @@ export function Scripts(props: ScriptProps) {
       : [
           "__remixContext.p = function(v,e,p,x) {",
           "  if (typeof e !== 'undefined') {",
-          "    x=new Error(e.message);",
-          process.env.NODE_ENV === "development" ? `x.stack=e.stack;` : "",
+          process.env.NODE_ENV === "development"
+            ? "    x=new Error(e.message);\n    x.stack=e.stack;"
+            : '    x=new Error("Unexpected Server Error");\n    x.stack=undefined;',
           "    p=Promise.reject(x);",
           "  } else {",
           "    p=Promise.resolve(v);",
@@ -835,8 +836,9 @@ export function Scripts(props: ScriptProps) {
           "__remixContext.r = function(i,k,v,e,p,x) {",
           "  p = __remixContext.t[i][k];",
           "  if (typeof e !== 'undefined') {",
-          "    x=new Error(e.message);",
-          process.env.NODE_ENV === "development" ? `x.stack=e.stack;` : "",
+          process.env.NODE_ENV === "development"
+            ? "    x=new Error(e.message);\n    x.stack=e.stack;"
+            : '    x=new Error("Unexpected Server Error");\n    x.stack=undefined;',
           "    p.e(x);",
           "  } else {",
           "    p.r(v);",
@@ -866,13 +868,16 @@ export function Scripts(props: ScriptProps) {
                 } else {
                   let trackedPromise = deferredData.data[key] as TrackedPromise;
                   if (typeof trackedPromise._error !== "undefined") {
-                    let toSerialize: { message: string; stack?: string } = {
-                      message: trackedPromise._error.message,
-                      stack: undefined,
-                    };
-                    if (process.env.NODE_ENV === "development") {
-                      toSerialize.stack = trackedPromise._error.stack;
-                    }
+                    let toSerialize: { message: string; stack?: string } =
+                      process.env.NODE_ENV === "development"
+                        ? {
+                            message: trackedPromise._error.message,
+                            stack: trackedPromise._error.stack,
+                          }
+                        : {
+                            message: "Unexpected Server Error",
+                            stack: undefined,
+                          };
                     return `${JSON.stringify(
                       key
                     )}:__remixContext.p(!1, ${escapeHtml(
@@ -1078,13 +1083,16 @@ function ErrorDeferredHydrationScript({
   routeId: string;
 }) {
   let error = useAsyncError() as Error;
-  let toSerialize: { message: string; stack?: string } = {
-    message: error.message,
-    stack: undefined,
-  };
-  if (process.env.NODE_ENV === "development") {
-    toSerialize.stack = error.stack;
-  }
+  let toSerialize: { message: string; stack?: string } =
+    process.env.NODE_ENV === "development"
+      ? {
+          message: error.message,
+          stack: error.stack,
+        }
+      : {
+          message: "Unexpected Server Error",
+          stack: undefined,
+        };
 
   return (
     <script