diff --git a/CHANGELOG.md b/CHANGELOG.md
index fe86bb74c568..6ff1c5cf22f9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@ Docs: https://docs.openclaw.ai
 ### Changes
 
 ### Fixes
+- Tests: fail the kitchen-sink RPC Docker walk when gateway RSS sampling is unavailable instead of silently disabling the per-process memory guard.
 - Tests: suppress the current Rolldown plugin timing warning format in the Vitest wrapper so tiny focused runs do not drown useful stderr in repeated build-timing noise.
 - Crabbox: sync clean sparse-checkout remote changed gates from a temporary full checkout with local-only commits overlaid as worktree changes so git-backed script checks can seed the runner repository.
 - Tests: make startup memory and startup bench smoke scripts build CLI startup artifacts when run from a fresh source checkout.
diff --git a/scripts/e2e/kitchen-sink-rpc-walk.mjs b/scripts/e2e/kitchen-sink-rpc-walk.mjs
index 916363c12163..1803a3969a94 100644
--- a/scripts/e2e/kitchen-sink-rpc-walk.mjs
+++ b/scripts/e2e/kitchen-sink-rpc-walk.mjs
@@ -588,7 +588,7 @@ async function sampleWindowsProcess(pid, run) {
 
 export function assertResourceCeiling(sample) {
   if (!sample) {
-    return;
+    throw new Error("gateway RSS sample was not captured");
   }
   if (sample.rssMiB > MAX_RSS_MIB) {
     throw new Error(`gateway RSS exceeded ${MAX_RSS_MIB} MiB: ${sample.rssMiB} MiB`);
diff --git a/test/scripts/kitchen-sink-rpc-walk.test.ts b/test/scripts/kitchen-sink-rpc-walk.test.ts
index b09173eb9100..421097f7fec4 100644
--- a/test/scripts/kitchen-sink-rpc-walk.test.ts
+++ b/test/scripts/kitchen-sink-rpc-walk.test.ts
@@ -52,4 +52,8 @@ describe("kitchen-sink RPC process sampling", () => {
       "gateway RSS exceeded 2048 MiB: 2049 MiB",
     );
   });
+
+  it("fails when process sampling does not capture RSS", () => {
+    expect(() => assertResourceCeiling(null)).toThrow("gateway RSS sample was not captured");
+  });
 });