diff --git a/internal/jobs/jobs.go b/internal/jobs/jobs.go
index 16f3b5f..583d75d 100644
--- a/internal/jobs/jobs.go
+++ b/internal/jobs/jobs.go
@@ -41,7 +41,9 @@ const (
 // Failure codes the runner stores itself. A kind cannot declare them.
 const (
 	// CodeInterrupted is the error of a job a previous process left running.
-	CodeInterrupted = "interrupted"
+	// It is fixed framework text, not a snake-case code, so no kind can
+	// declare it.
+	CodeInterrupted = "interrupted by restart"
 	// CodeInternal is the error of a job whose handler failed with anything
 	// but a *Failure with a code its kind declared, or whose payload or
 	// result could not be encoded. The underlying error is neither stored
@@ -152,7 +154,7 @@ func Register[P any, R Public](r *Runner, kind string, h Handler[P, R], failureC
 		if !codePattern.MatchString(code) {
 			return nil, fmt.Errorf("jobs: register %q: failure code %q is not lower-case snake case", kind, code)
 		}
-		if code == CodeInterrupted || code == CodeInternal || code == CodeUnknownKind {
+		if code == CodeInternal || code == CodeUnknownKind {
 			return nil, fmt.Errorf("jobs: register %q: failure code %q is reserved for the runner", kind, code)
 		}
 		declared[code] = true
diff --git a/internal/jobs/jobs_test.go b/internal/jobs/jobs_test.go
index 6ea3239..7a3395d 100644
--- a/internal/jobs/jobs_test.go
+++ b/internal/jobs/jobs_test.go
@@ -391,8 +391,8 @@ func TestRestartFailsInterruptedJobsAndRunsQueuedOnes(t *testing.T) {
 	start(t, second)
 
 	job := waitFor(t, second, interrupted, finished)
-	if job.Status != StatusFailed || job.Error == nil || *job.Error != CodeInterrupted {
-		t.Errorf("interrupted job = %+v, want failed with %q", job, CodeInterrupted)
+	if job.Status != StatusFailed || job.Error == nil || *job.Error != "interrupted by restart" {
+		t.Errorf("interrupted job = %+v, want failed with %q", job, "interrupted by restart")
 	}
 	if string(job.Result) != `{"done":1}` {
 		t.Errorf("interrupted job result = %s, want the last partial result kept", job.Result)