diff --git a/server/internal/postgresx/acquisition_value_hints.go b/server/internal/postgresx/acquisition_value_hints.go
index df2e75a1a..a656536a5 100644
--- a/server/internal/postgresx/acquisition_value_hints.go
+++ b/server/internal/postgresx/acquisition_value_hints.go
@@ -93,7 +93,8 @@ func (a Acquisition) CompleteValueHint(ctx context.Context, scope collectnative.
 	}
 	var retryAt any
 	if !retry.IsZero() {
-		retryAt = retry.UTC()
+		// timestamptz stores microseconds and rounds; truncate so retry_at round-trips exactly.
+		retryAt = retry.UTC().Truncate(time.Microsecond)
 	}
 	result, err := tx.ExecContext(ctx, `UPDATE cao_acquisition_value_hints SET
 		processed=CASE WHEN $6::timestamptz IS NULL THEN greatest(processed,$4) ELSE processed END,
diff --git a/server/internal/postgresx/acquisition_value_hints_test.go b/server/internal/postgresx/acquisition_value_hints_test.go
index 4a677e649..d7e5022ed 100644
--- a/server/internal/postgresx/acquisition_value_hints_test.go
+++ b/server/internal/postgresx/acquisition_value_hints_test.go
@@ -47,7 +47,7 @@ func TestNativeValueHintsFenceConcurrentInvalidationAndAcknowledgement(t *testin
 	if err := a.InvalidateValue(t.Context(), scope); err != nil {
 		t.Fatal(err)
 	}
-	now := time.Now().UTC()
+	now := time.Now().UTC().Truncate(time.Microsecond)
 	if err := b.CompleteValueHint(t.Context(), scope, hint.Dirty, now, time.Time{}); err != nil {
 		t.Fatal(err)
 	}