diff --git a/keda/src/components/common/CommonComponents.test.ts b/keda/src/components/common/CommonComponents.test.ts
new file mode 100644
index 0000000000..647cd97798
--- /dev/null
+++ b/keda/src/components/common/CommonComponents.test.ts
@@ -0,0 +1,35 @@
+import { describe, expect, it } from 'vitest';
+import { getCompletions, sortByCompletions } from './CommonComponents';
+
+function job(completions?: number, parallelism?: number) {
+  return { spec: { completions, parallelism } } as any;
+}
+
+describe('sortByCompletions', () => {
+  it('sorts by completions, not parallelism, when they disagree', () => {
+    // job1 has fewer completions but more parallelism than job2 — a completions-first
+    // sort must put job1 before job2, the opposite of what a parallelism-first sort would do.
+    expect(sortByCompletions(job(1, 5), job(5, 1))).toBeLessThan(0);
+  });
+
+  it('falls back to parallelism when completions are equal', () => {
+    expect(sortByCompletions(job(2, 1), job(2, 4))).toBeLessThan(0);
+  });
+
+  it('treats missing completions/parallelism as 0 instead of NaN', () => {
+    expect(sortByCompletions(job(undefined, undefined), job(1, 1))).toBeLessThan(0);
+    expect(
+      Number.isNaN(sortByCompletions(job(undefined, undefined), job(undefined, undefined)))
+    ).toBe(false);
+  });
+});
+
+describe('getCompletions', () => {
+  it('renders both fields when set', () => {
+    expect(getCompletions(job(1, 5))).toBe('1/5');
+  });
+
+  it('renders 0 instead of undefined for unset fields, matching how they sort', () => {
+    expect(getCompletions(job(undefined, undefined))).toBe('0/0');
+  });
+});
diff --git a/keda/src/components/common/CommonComponents.tsx b/keda/src/components/common/CommonComponents.tsx
index f25cfea7b8..9258d8734d 100644
--- a/keda/src/components/common/CommonComponents.tsx
+++ b/keda/src/components/common/CommonComponents.tsx
@@ -564,22 +564,22 @@ export interface JobsListRendererProps {
   noNamespaceFilter?: boolean;
 }
 
+export function sortByCompletions(job1: Job, job2: Job) {
+  const completionsSorted = (job1.spec.completions ?? 0) - (job2.spec.completions ?? 0);
+  if (completionsSorted === 0) {
+    return (job1.spec.parallelism ?? 0) - (job2.spec.parallelism ?? 0);
+  }
+  return completionsSorted;
+}
+
+export function getCompletions(job: Job) {
+  return `${job.spec.completions ?? 0}/${job.spec.parallelism ?? 0}`;
+}
+
 export function JobsListRenderer(props: JobsListRendererProps) {
   const { jobs, errors, hideColumns = [], reflectTableInURL = 'jobs', noNamespaceFilter } = props;
   const { t } = useTranslation();
 
-  function getCompletions(job: Job) {
-    return `${job.spec.completions}/${job.spec.parallelism}`;
-  }
-
-  function sortByCompletions(job1: Job, job2: Job) {
-    const parallelismSorted = job1.spec.parallelism - job2.spec.parallelism;
-    if (parallelismSorted === 0) {
-      return job1.spec.completions - job2.spec.completions;
-    }
-    return parallelismSorted;
-  }
-
   return (
     <ResourceListView
       title={t('Jobs')}