diff --git a/CHANGELOG.md b/CHANGELOG.md
index e69de29bb..8be4ad4e0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -0,0 +1 @@
+- fix: Remove false warning when using Expression in cors option #1802
diff --git a/spec/v2/providers/https.spec.ts b/spec/v2/providers/https.spec.ts
index a62dfea5a..7a8bef55a 100644
--- a/spec/v2/providers/https.spec.ts
+++ b/spec/v2/providers/https.spec.ts
@@ -32,7 +32,14 @@ import { FULL_ENDPOINT, MINIMAL_V2_ENDPOINT, FULL_OPTIONS, FULL_TRIGGER } from "
 import { onInit } from "../../../src/v2/core";
 import { Handler } from "express";
 import { genkit } from "genkit";
-import { clearParams, defineBoolean, defineList, Expression } from "../../../src/params";
+import {
+  clearParams,
+  defineBoolean,
+  defineList,
+  defineString,
+  Expression,
+} from "../../../src/params";
+import { logger } from "../../../src/logger";
 
 function request(args: {
   data?: any;
@@ -59,6 +66,41 @@ function request(args: {
   return ret;
 }
 
+async function testWarningForCorsExpression(
+  createFunc: (options: { cors: Expression<string[]> }) => https.HttpsFunction,
+  origin: string
+) {
+  const loggerSpy = sinon.spy(logger, "warn");
+  const projectId = defineString("PROJECT_ID");
+
+  try {
+    process.env.PROJECT_ID = "test-project";
+    process.env.FUNCTIONS_CONTROL_API = "true";
+
+    const corsExpression = projectId.equals("test-project").thenElse([origin], []);
+    const func = createFunc({ cors: corsExpression });
+
+    const req = request({
+      headers: {
+        referrer: origin,
+        "content-type": "application/json",
+        origin: origin,
+      },
+      method: "OPTIONS",
+    });
+
+    const response = await runHandler(func, req);
+
+    expect(response.status).to.equal(204);
+    expect(loggerSpy.called).to.be.false;
+  } finally {
+    delete process.env.PROJECT_ID;
+    delete process.env.FUNCTIONS_CONTROL_API;
+    clearParams();
+    loggerSpy.restore();
+  }
+}
+
 describe("onRequest", () => {
   beforeEach(() => {
     options.setGlobalOptions({});
@@ -336,6 +378,16 @@ describe("onRequest", () => {
     await runHandler(func, req);
     expect(hello).to.equal("world");
   });
+
+  it("should not warn when using Expression-based cors config during deployment", async () => {
+    await testWarningForCorsExpression(
+      (opts) =>
+        https.onRequest(opts, (req, res) => {
+          res.send("42");
+        }),
+      "http://localhost:8000"
+    );
+  });
 });
 
 describe("onCall", () => {
@@ -605,6 +657,13 @@ describe("onCall", () => {
     expect(hello).to.equal("world");
   });
 
+  it("should not warn when using Expression-based cors config during deployment", async () => {
+    await testWarningForCorsExpression(
+      (opts) => https.onCall(opts, () => 42),
+      "http://localhost:5173"
+    );
+  });
+
   describe("authPolicy", () => {
     before(() => {
       sinon.stub(debug, "isDebugFeatureEnabled").withArgs("skipTokenVerification").returns(true);
diff --git a/src/v2/providers/https.ts b/src/v2/providers/https.ts
index cfb3cfee3..9772e210c 100644
--- a/src/v2/providers/https.ts
+++ b/src/v2/providers/https.ts
@@ -324,7 +324,7 @@ export function onRequest(
   handler = withErrorHandler(handler);
 
   if (isDebugFeatureEnabled("enableCors") || "cors" in opts) {
-    let origin = opts.cors instanceof Expression ? opts.cors.value() : opts.cors;
+    let origin = opts.cors instanceof Expression ? opts.cors.runtimeValue() : opts.cors;
     if (isDebugFeatureEnabled("enableCors")) {
       // Respect `cors: false` to turn off cors even if debug feature is enabled.
       origin = opts.cors === false ? false : true;
@@ -437,7 +437,7 @@ export function onCall<T = any, Return = any | Promise<any>, Stream = unknown>(
   let cors: string | boolean | RegExp | Array<string | RegExp> | undefined;
   if ("cors" in opts) {
     if (opts.cors instanceof Expression) {
-      cors = opts.cors.value();
+      cors = opts.cors.runtimeValue();
     } else {
       cors = opts.cors;
     }