diff --git a/lib/ci/build-types/normal_build.js b/lib/ci/build-types/normal_build.js
index 7c148b78..e7d541b4 100644
--- a/lib/ci/build-types/normal_build.js
+++ b/lib/ci/build-types/normal_build.js
@@ -76,7 +76,7 @@ export class NormalBuild extends Job {
       if (!upstream) {
         return true;
       } else {
-        return this.jobUrl.includes(upstream + '');
+        return this.jobUrl.endsWith(`/${upstream}/`);
       }
     });
 
diff --git a/lib/ci/build-types/test_run.js b/lib/ci/build-types/test_run.js
index 8d60dcf8..46f2364f 100644
--- a/lib/ci/build-types/test_run.js
+++ b/lib/ci/build-types/test_run.js
@@ -31,7 +31,7 @@ export class TestRun extends Job {
       ];
       return this.failures;
     }
-    this.causes = this.getCause(data.actions) || {};
+    this.cause = this.getCause(data.actions) || {};
     this.builtOn = data.builtOn;
   }
 
diff --git a/test/unit/ci_normal_build.test.js b/test/unit/ci_normal_build.test.js
new file mode 100644
index 00000000..5c169eee
--- /dev/null
+++ b/test/unit/ci_normal_build.test.js
@@ -0,0 +1,72 @@
+import { describe, it } from 'node:test';
+import assert from 'node:assert/strict';
+
+import { NormalBuild } from '../../lib/ci/build-types/normal_build.js';
+import TestCLI from '../fixtures/test_cli.js';
+
+const jobName = 'node-test-commit-osx';
+const jobURL = `https://ci.nodejs.org/job/${jobName}/`;
+const currentURL = `${jobURL}nodes=macos15-x64/73204/`;
+const failureLog = 'not ok 1 parallel/test-example\n' +
+  '  ---\n  severity: fail\n  stack: |-\n    AssertionError\n  ...\n';
+
+describe('Jenkins matrix failure reporting', () => {
+  for (const { name, upstreamBuild, reportRun } of [
+    { name: 'ignores an older run', upstreamBuild: 73203, reportRun: false },
+    { name: 'ignores a build-number prefix', upstreamBuild: 7320, reportRun: false },
+    { name: 'ignores a build-number suffix', upstreamBuild: 3204, reportRun: false },
+    { name: 'keeps runs without an upstream cause', reportRun: true }
+  ]) {
+    it(name, async(t) => {
+      const otherURL = `${jobURL}nodes=osx13-x64/${upstreamBuild ?? 73204}/`;
+      const responses = new Map([
+        [`${jobURL}73204/api/json`, {
+          result: 'FAILURE',
+          runs: [
+            { number: 73204, result: 'FAILURE', url: currentURL },
+            { number: upstreamBuild ?? 73204, result: 'FAILURE', url: otherURL }
+          ]
+        }],
+        [`${currentURL}api/json`, {
+          builtOn: 'current-worker',
+          actions: [{}, {
+            causes: [{ upstreamBuild: 73204, upstreamProject: jobName }]
+          }]
+        }],
+        [`${otherURL}api/json`, {
+          builtOn: 'other-worker',
+          actions: upstreamBuild === undefined
+            ? []
+            : [{}, {
+                causes: [{ upstreamBuild, upstreamProject: jobName }]
+              }]
+        }]
+      ]);
+      const request = {
+        async json(url) {
+          const key = url.split('?')[0];
+          assert.ok(responses.has(key), `Unexpected JSON request: ${url}`);
+          return responses.get(key);
+        },
+        text: t.mock.fn(async() => failureLog)
+      };
+      const build = new NormalBuild(new TestCLI(), request, jobName, 73204);
+      const failures = await build.getResults();
+      const expectedURLs = reportRun ? [currentURL, otherURL] : [currentURL];
+
+      assert.deepEqual(failures.map(failure => ({
+        url: failure.url,
+        type: failure.type,
+        file: failure.file
+      })), expectedURLs.map(url => ({
+        url: `${url}console`,
+        type: 'JS_TEST_FAILURE',
+        file: 'parallel/test-example'
+      })));
+      assert.deepEqual(
+        request.text.mock.calls.map(call => call.arguments),
+        expectedURLs.map(url => [`${url}consoleText`])
+      );
+    });
+  }
+});