diff --git a/modules/mesh-delivery-pipeline/internal/pipeline/steps.go b/modules/mesh-delivery-pipeline/internal/pipeline/steps.go
index 4781a04d..e239c575 100644
--- a/modules/mesh-delivery-pipeline/internal/pipeline/steps.go
+++ b/modules/mesh-delivery-pipeline/internal/pipeline/steps.go
@@ -272,8 +272,8 @@ func stepOfAsk(p seat.Pipeline, id string) int {
 }
 
 // endPipeline ends a pipeline whose every step ended: passed when every required step passed or was carried, else
-// failed, naming each required step that held it (ADR 0666 §7, §9; design 47 G §24, §26). A failed optional step holds
-// nothing. An approval step still waiting when a required step did not pass is `not asked` (§26). It says whether the
+// failed, naming each required step that held it (ADR 0666 §7, §9; design 47 G §24, §26). A failed optional step, and an optional step
+// still waiting, hold nothing. An approval step still waiting when a required step did not pass is `not asked` (§26). It says whether the
 // pipeline ended now, its end count one higher.
 func endPipeline(p *seat.Pipeline, now time.Time) bool {
 	if p.Outcome != seat.PipelineOutcomeRunning {
@@ -286,6 +286,10 @@ func endPipeline(p *seat.Pipeline, now time.Time) bool {
 		case s.Step == seat.StepResultStepApproval && s.Outcome == seat.StepResultOutcomeWaiting:
 			notAsked = i
 			continue
+		case s.Outcome == seat.StepResultOutcomeWaiting && s.Status != seat.StepResultStatusRequired:
+			// An optional step still waiting (a code review nobody has given) holds nothing: only a required one holds the
+			// pipeline's end (A-104).
+			continue
 		case s.Outcome == seat.StepResultOutcomeWaiting, s.Outcome == seat.StepResultOutcomeRunning:
 			return false
 		}
diff --git a/modules/mesh-delivery-pipeline/internal/pipeline/steps_test.go b/modules/mesh-delivery-pipeline/internal/pipeline/steps_test.go
index 3f6c18bc..331cb6b8 100644
--- a/modules/mesh-delivery-pipeline/internal/pipeline/steps_test.go
+++ b/modules/mesh-delivery-pipeline/internal/pipeline/steps_test.go
@@ -276,3 +276,25 @@ func TestApprovalEnds(t *testing.T) {
 		t.Errorf("asked %d; %+v", len(asker.asked), p)
 	}
 }
+
+// An optional step still waiting (a code review nobody has given) does not hold a pipeline's end; a required one does
+// (design 47 G A-104).
+func TestAnOptionalStepStillWaitingHoldsNoEnd(t *testing.T) {
+	now := time.Date(2026, 11, 11, 12, 0, 0, 0, time.UTC)
+	for name, c := range map[string]struct {
+		review string
+		ends   bool
+	}{"optional review waiting": {seat.StepResultStatusOptional, true}, "required review waiting": {seat.StepResultStatusRequired, false}} {
+		p := seat.Pipeline{Outcome: seat.PipelineOutcomeRunning, Steps: []seat.StepResult{
+			{Step: seat.StepResultStepBuild, Status: seat.StepResultStatusRequired, Outcome: seat.StepResultOutcomePassed},
+			{Step: seat.StepResultStepReview, Status: c.review, Outcome: seat.StepResultOutcomeWaiting},
+			{Step: seat.StepResultStepApproval, Status: seat.StepResultStatusRequired, Outcome: seat.StepResultOutcomePassed},
+		}}
+		if got := endPipeline(&p, now); got != c.ends {
+			t.Errorf("%s: ended = %v, want %v", name, got, c.ends)
+		}
+		if c.ends && p.Outcome != seat.PipelineOutcomePassed {
+			t.Errorf("%s: outcome %s", name, p.Outcome)
+		}
+	}
+}