diff --git a/kits/storage-resize-images/src/config.ts b/kits/storage-resize-images/src/config.ts
index 9902641f79..b7850ed4d9 100644
--- a/kits/storage-resize-images/src/config.ts
+++ b/kits/storage-resize-images/src/config.ts
@@ -285,6 +285,26 @@ function optional(value: string): string | undefined {
   return value.length > 0 ? value : undefined;
 }
 
+/**
+ * `ListParam.value()` JSON-parses the raw env var. Extension-style values may
+ * either throw (for example, `jpeg,webp`) or parse to a non-list and collapse
+ * to `[]` (notably the extension default, `false`). The extension read the raw
+ * value directly, so preserve it whenever the params layer cannot return a
+ * non-empty list and let the resolver's `toArray` apply legacy semantics.
+ */
+function imageTypesFromEnv(): ReadonlyArray<string> | string | undefined {
+  const raw = process.env.IMAGE_TYPE;
+  if (raw === undefined) {
+    return undefined;
+  }
+  try {
+    const parsed = params.imageTypes.value();
+    return parsed.length > 0 ? parsed : raw;
+  } catch {
+    return raw;
+  }
+}
+
 export function configFromEnv(): ResizeImagesConfig {
   return {
     bucket: params.bucket.value(),
@@ -296,11 +316,14 @@ export function configFromEnv(): ResizeImagesConfig {
     excludePathList: optional(params.excludePathList.value()),
     failedImagesPath: optional(params.failedImagesPath.value()),
     cacheControlHeader: optional(params.cacheControlHeader.value()),
-    imageTypes: params.imageTypes.value(),
+    imageTypes: imageTypesFromEnv(),
     outputOptions: optional(params.outputOptions.value()),
     sharpOptions: params.sharpOptions.value(),
     isAnimated: params.isAnimated.value(),
-    memory: params.memory.value(),
+    // IntParam yields 0 when FUNCTION_MEMORY is unset or non-numeric; the
+    // extension always supplied a value, so treat that as unset and let the
+    // resolver fall back to the default memory.
+    memory: params.memory.value() || undefined,
     regenerateToken: params.regenerateToken.value(),
     contentFilterLevel:
       params.contentFilterLevel.value() as ResizeImagesConfig["contentFilterLevel"],
diff --git a/kits/storage-resize-images/tests/config.test.ts b/kits/storage-resize-images/tests/config.test.ts
index 7ecaeef67d..966bf94961 100644
--- a/kits/storage-resize-images/tests/config.test.ts
+++ b/kits/storage-resize-images/tests/config.test.ts
@@ -102,6 +102,53 @@ describe("configFromEnv", () => {
     expect(config.projectId).toBe("extensions-testing");
   });
 
+  // The extension read process.env directly and degraded gracefully against a
+  // partial environment; the params layer must not turn that into a cold-start
+  // crash (ListParam JSON-parses IMAGE_TYPE, IntParam yields 0 for
+  // FUNCTION_MEMORY).
+  test("survives an unset IMAGE_TYPE", async () => {
+    delete process.env.IMAGE_TYPE;
+    const { configFromEnv } = await import("../src/config");
+    const { resolveResizeImagesConfig } = await import("../src/export-config");
+
+    const config = configFromEnv();
+    expect(config.imageTypes).toBeUndefined();
+    expect(resolveResizeImagesConfig(config).imageTypes).toEqual(["false"]);
+  });
+
+  test("accepts the extension-style IMAGE_TYPE=false default", async () => {
+    process.env.IMAGE_TYPE = "false";
+    const { configFromEnv } = await import("../src/config");
+    const { resolveResizeImagesConfig } = await import("../src/export-config");
+
+    const config = configFromEnv();
+    expect(config.imageTypes).toBe("false");
+    expect(resolveResizeImagesConfig(config).imageTypes).toEqual(["false"]);
+  });
+
+  test("accepts an extension-style comma-separated IMAGE_TYPE", async () => {
+    process.env.IMAGE_TYPE = "jpeg,webp";
+    const { configFromEnv } = await import("../src/config");
+    const { resolveResizeImagesConfig } = await import("../src/export-config");
+
+    const config = configFromEnv();
+    expect(config.imageTypes).toBe("jpeg,webp");
+    expect(resolveResizeImagesConfig(config).imageTypes).toEqual([
+      "jpeg",
+      "webp",
+    ]);
+  });
+
+  test("falls back to the default memory when FUNCTION_MEMORY is unset", async () => {
+    delete process.env.FUNCTION_MEMORY;
+    const { configFromEnv } = await import("../src/config");
+    const { resolveResizeImagesConfig } = await import("../src/export-config");
+
+    const config = configFromEnv();
+    expect(config.memory).toBeUndefined();
+    expect(resolveResizeImagesConfig(config).memory).toBe("1GiB");
+  });
+
   test("collapses unset optional strings to undefined", async () => {
     const { configFromEnv } = await import("../src/config");
     const config = configFromEnv();
@@ -133,6 +180,8 @@ describe("configFromEnv", () => {
     // runtime contract. `.value()` reads only `process.env`; the declared
     // `default:` is written into the deployed `.env` by the CLI. A hand-rolled
     // or partial `.env` therefore yields these values, not the declared ones.
+    // (memory is the exception: configFromEnv maps IntParam's 0 sentinel to
+    // undefined so the resolver can apply its default.)
     delete process.env.IS_ANIMATED;
     delete process.env.REGENERATE_TOKEN;
     delete process.env.FUNCTION_MEMORY;
@@ -143,31 +192,10 @@ describe("configFromEnv", () => {
 
     expect(config.isAnimated).toBe(false);
     expect(config.regenerateToken).toBe(false);
-    expect(config.memory).toBe(0);
+    expect(config.memory).toBeUndefined();
     expect(config.sharpOptions).toBe("");
   });
 
-  test("a missing IMAGE_TYPE throws instead of falling back to its default", async () => {
-    // The list param JSON-parses the raw env var, so an absent IMAGE_TYPE is
-    // a cold-start crash — the kit's counterpart to the extension's
-    // `IMG_SIZES.split(",")` TypeError on a missing variable.
-    delete process.env.IMAGE_TYPE;
-
-    const { configFromEnv } = await import("../src/config");
-    expect(() => configFromEnv()).toThrow(SyntaxError);
-  });
-
-  test("IMAGE_TYPE is read as a JSON array, not a comma-separated string", async () => {
-    // The extension reads the same variable with `.split(",")`, so an
-    // extension-style value does not carry over.
-    process.env.IMAGE_TYPE = "jpeg,webp";
-    const { configFromEnv } = await import("../src/config");
-    expect(() => configFromEnv()).toThrow(SyntaxError);
-
-    process.env.IMAGE_TYPE = '["jpeg","webp"]';
-    expect(configFromEnv().imageTypes).toEqual(["jpeg", "webp"]);
-  });
-
   test("reads explicit values for every param", async () => {
     Object.assign(process.env, {
       IMG_SIZES: "200x200,400x400",