diff --git a/scripts/e2e/Dockerfile.qr-import b/scripts/e2e/Dockerfile.qr-import
index a235a7f4bd2..e221e0278a9 100644
--- a/scripts/e2e/Dockerfile.qr-import
+++ b/scripts/e2e/Dockerfile.qr-import
@@ -10,6 +10,9 @@ COPY package.json pnpm-lock.yaml pnpm-workspace.yaml ./
 COPY ui/package.json ./ui/package.json
 COPY patches ./patches
 
+# This image only exercises the root qrcode-terminal dependency path.
+# Keep the pre-install copy set limited to the manifests needed for root
+# workspace resolution so unrelated extension edits do not bust the layer.
 RUN --mount=type=cache,id=openclaw-pnpm-store,target=/root/.local/share/pnpm/store,sharing=locked \
     pnpm install --frozen-lockfile
 
diff --git a/src/docker-build-cache.test.ts b/src/docker-build-cache.test.ts
index 08ff562099f..99df5d4e430 100644
--- a/src/docker-build-cache.test.ts
+++ b/src/docker-build-cache.test.ts
@@ -106,6 +106,14 @@ describe("docker build cache layout", () => {
       dockerfile.indexOf("COPY package.json pnpm-lock.yaml pnpm-workspace.yaml ./"),
     ).toBeLessThan(installIndex);
     expect(dockerfile.indexOf("COPY ui/package.json ./ui/package.json")).toBeLessThan(installIndex);
+    expect(dockerfile).toContain(
+      "This image only exercises the root qrcode-terminal dependency path.",
+    );
+    expect(
+      dockerfile.indexOf(
+        "COPY extensions/memory-core/package.json ./extensions/memory-core/package.json",
+      ),
+    ).toBe(-1);
     expect(dockerfile.indexOf("COPY . .")).toBeGreaterThan(installIndex);
   });
 });