diff --git a/rate/sometimes.go b/rate/sometimes.go
index 6ba99dd..9b83932 100644
--- a/rate/sometimes.go
+++ b/rate/sometimes.go
@@ -61,7 +61,9 @@
 		(s.Every > 0 && s.count%s.Every == 0) ||
 		(s.Interval > 0 && time.Since(s.last) >= s.Interval) {
 		f()
-		s.last = time.Now()
+		if s.Interval > 0 {
+			s.last = time.Now()
+		}
 	}
 	s.count++
 }
diff --git a/rate/sometimes_test.go b/rate/sometimes_test.go
index 6781770..b1c06fd 100644
--- a/rate/sometimes_test.go
+++ b/rate/sometimes_test.go
@@ -92,3 +92,18 @@
 	s.Do(func() {})
 	s.Do(func() {})
 }
+
+func BenchmarkSometimes(b *testing.B) {
+	b.Run("no-interval", func(b *testing.B) {
+		s := rate.Sometimes{Every: 10}
+		for i := 0; i < b.N; i++ {
+			s.Do(func() {})
+		}
+	})
+	b.Run("with-interval", func(b *testing.B) {
+		s := rate.Sometimes{Interval: time.Second}
+		for i := 0; i < b.N; i++ {
+			s.Do(func() {})
+		}
+	})
+}