diff --git a/bar.go b/bar.go
index d629e78..6e062b9 100644
--- a/bar.go
+++ b/bar.go
@@ -203,18 +203,23 @@
 	b.arbitraryCurrent.Unlock()
 }
 
-// Increment is a shorthand for b.IncrBy(1).
-func (b *Bar) Increment() {
-	b.IncrBy(1)
-}
-
-// IncrBy increments progress bar by amount of n.
-// wdd is optional work duration i.e. time.Since(start), which expected
-// to be provided, if any ewma based decorator is used.
+// Increment is a shorthand for b.IncrInt64(1).
+func (b *Bar) Increment(wdd ...time.Duration) {
+	b.IncrInt64(1, wdd...)
+}
+
+// IncrBy is a shorthand for b.IncrInt64(int64(n), wdd...).
 func (b *Bar) IncrBy(n int, wdd ...time.Duration) {
+	b.IncrInt64(int64(n), wdd...)
+}
+
+// IncrInt64 increments progress bar by amount of n. wdd is an optional
+// work duration i.e. time.Since(start), which expected to be passed,
+// if any ewma based decorator is used.
+func (b *Bar) IncrInt64(n int64, wdd ...time.Duration) {
 	select {
 	case b.operateState <- func(s *bState) {
-		s.current += int64(n)
+		s.current += n
 		if s.total > 0 && s.current >= s.total {
 			s.current = s.total
 			s.toComplete = true
diff --git a/decor/decorator.go b/decor/decorator.go
index ee93ff0..b699d48 100644
--- a/decor/decorator.go
+++ b/decor/decorator.go
@@ -83,7 +83,7 @@
 // If decorator needs to receive increment amount, so this is the right
 // interface to implement.
 type AmountReceiver interface {
-	NextAmount(int, ...time.Duration)
+	NextAmount(int64, ...time.Duration)
 }
 
 // ShutdownListener interface.
diff --git a/decor/eta.go b/decor/eta.go
index e62c01f..5941204 100644
--- a/decor/eta.go
+++ b/decor/eta.go
@@ -98,7 +98,7 @@
 	return d.FormatMsg(str)
 }
 
-func (d *movingAverageETA) NextAmount(n int, wdd ...time.Duration) {
+func (d *movingAverageETA) NextAmount(n int64, wdd ...time.Duration) {
 	var workDuration time.Duration
 	for _, wd := range wdd {
 		workDuration = wd
diff --git a/decor/speed.go b/decor/speed.go
index a36bb6d..08314b3 100644
--- a/decor/speed.go
+++ b/decor/speed.go
@@ -192,7 +192,7 @@
 	return d.FormatMsg(d.msg)
 }
 
-func (d *movingAverageSpeed) NextAmount(n int, wdd ...time.Duration) {
+func (d *movingAverageSpeed) NextAmount(n int64, wdd ...time.Duration) {
 	var workDuration time.Duration
 	for _, wd := range wdd {
 		workDuration = wd