diff --git a/src/browser/modules/NativeModuleResolver.test.ts b/src/browser/modules/NativeModuleResolver.test.ts
index 044576ac13..1619e8fc44 100644
--- a/src/browser/modules/NativeModuleResolver.test.ts
+++ b/src/browser/modules/NativeModuleResolver.test.ts
@@ -167,6 +167,26 @@ describe("optional native resolution acquisition", () => {
         message: expect.stringContaining("REA_BROWSER_EXECUTABLE"),
       });
   });
+  it.each(["relative/chromium", ""])(
+    "retains an invalid selected browser path %j without launching",
+    async (executable) => {
+      const provider = new NativeModuleResolver(
+        { REA_BROWSER_EXECUTABLE: executable },
+        () => {
+          throw new Error("must not launch");
+        },
+      );
+      const result = await provider.resolve(input);
+      if (result.ok) throw new Error("expected configuration refusal");
+      expect(projectAnalysisError(result.error)).toMatchObject({
+        code: "capability_unavailable",
+        details: {
+          reason: "invalid_browser_executable",
+          diagnostics: { executable },
+        },
+      });
+    },
+  );
   it("does not acquire a browser after caller cancellation", async () => {
     const controller = new AbortController();
     const reason = { request: "opaque admission cancellation" };
diff --git a/src/browser/modules/NativeModuleResolver.ts b/src/browser/modules/NativeModuleResolver.ts
index 9bf0ba59dc..4383a27e0c 100644
--- a/src/browser/modules/NativeModuleResolver.ts
+++ b/src/browser/modules/NativeModuleResolver.ts
@@ -119,10 +119,15 @@ export class NativeModuleResolver implements WebModuleResolutionPort {
         new AnalysisCapabilityUnavailableError(
           "native-module-resolver",
           OPERATION,
-          "missing_browser_executable",
+          executable === undefined
+            ? "missing_browser_executable"
+            : "invalid_browser_executable",
           {
             userMessage:
               "Provide an absolute REA_BROWSER_EXECUTABLE for a caller-supplied Chromium browser supporting import.meta.resolve. REA installs no browser.",
+            ...(executable === undefined
+              ? {}
+              : { diagnostics: { executable } }),
           },
         ),
       );
diff --git a/tests/acceptance/webModuleCli.test.ts b/tests/acceptance/webModuleCli.test.ts
index 57509e6770..468d1551b9 100644
--- a/tests/acceptance/webModuleCli.test.ts
+++ b/tests/acceptance/webModuleCli.test.ts
@@ -136,3 +136,35 @@ cliTest(
     }
   },
 );
+
+cliTest(
+  "retains an invalid caller-selected browser path in trace errors",
+  async ({ cli }) => {
+    const root = await createTestTempDirectory("rea-module-browser-config-");
+    const artifacts = webModuleArtifactsFixture('import "./dep.js"');
+    const files = join(root, "files");
+    await mkdir(join(files, "modules"), { recursive: true });
+    await writeFile(join(files, "modules", "main.js"), artifacts.source);
+    const manifest = join(root, "manifest.json");
+    await writeFile(
+      manifest,
+      JSON.stringify({
+        ...artifacts.manifest,
+        output_directory: root,
+        analysis_input: { input_path: files, format: "directory" },
+      }),
+    );
+    const result = await cli.run({
+      arguments: ["trace-web-module-imports", manifest, "0", "--json"],
+      environment: { REA_BROWSER_EXECUTABLE: "relative/chromium" },
+    });
+    expect(result.exitCode).toBe(1);
+    expect(result.json).toMatchObject({
+      code: "capability_unavailable",
+      details: {
+        reason: "invalid_browser_executable",
+        diagnostics: { executable: "relative/chromium" },
+      },
+    });
+  },
+);