diff --git a/priority-queue.go b/priority-queue.go
deleted file mode 100644
index f60e222..0000000
--- a/priority-queue.go
+++ /dev/null
@@ -1,70 +0,0 @@
-package mpb
-
-import "container/heap"
-
-// A priorityQueue implements heap.Interface and holds Items.
-type priorityQueue []*Bar
-
-func (pq priorityQueue) Len() int { return len(pq) }
-
-func (pq priorityQueue) Less(i, j int) bool {
-	return pq[i].priority < pq[j].priority
-}
-
-func (pq priorityQueue) Swap(i, j int) {
-	pq[i], pq[j] = pq[j], pq[i]
-	pq[i].index = i
-	pq[j].index = j
-}
-
-func (pq *priorityQueue) Push(x interface{}) {
-	n := len(*pq)
-	bar := x.(*Bar)
-	bar.index = n
-	*pq = append(*pq, bar)
-}
-
-func (pq *priorityQueue) Pop() interface{} {
-	old := *pq
-	n := len(old)
-	bar := old[n-1]
-	bar.index = -1 // for safety
-	*pq = old[0 : n-1]
-	return bar
-}
-
-// update modifies the priority of an Bar in the queue.
-func (pq *priorityQueue) update(bar *Bar, priority int) {
-	bar.priority = priority
-	heap.Fix(pq, bar.index)
-}
-
-func (pq priorityQueue) maxNumP() int {
-	if pq.Len() == 0 {
-		return 0
-	}
-
-	max := pq[0].NumOfPrependers()
-	for i := 1; i < pq.Len(); i++ {
-		n := pq[i].NumOfPrependers()
-		if n > max {
-			max = n
-		}
-	}
-	return max
-}
-
-func (pq priorityQueue) maxNumA() int {
-	if pq.Len() == 0 {
-		return 0
-	}
-
-	max := pq[0].NumOfAppenders()
-	for i := 1; i < pq.Len(); i++ {
-		n := pq[i].NumOfAppenders()
-		if n > max {
-			max = n
-		}
-	}
-	return max
-}
diff --git a/priority_queue.go b/priority_queue.go
new file mode 100644
index 0000000..f60e222
--- /dev/null
+++ b/priority_queue.go
@@ -0,0 +1,70 @@
+package mpb
+
+import "container/heap"
+
+// A priorityQueue implements heap.Interface and holds Items.
+type priorityQueue []*Bar
+
+func (pq priorityQueue) Len() int { return len(pq) }
+
+func (pq priorityQueue) Less(i, j int) bool {
+	return pq[i].priority < pq[j].priority
+}
+
+func (pq priorityQueue) Swap(i, j int) {
+	pq[i], pq[j] = pq[j], pq[i]
+	pq[i].index = i
+	pq[j].index = j
+}
+
+func (pq *priorityQueue) Push(x interface{}) {
+	n := len(*pq)
+	bar := x.(*Bar)
+	bar.index = n
+	*pq = append(*pq, bar)
+}
+
+func (pq *priorityQueue) Pop() interface{} {
+	old := *pq
+	n := len(old)
+	bar := old[n-1]
+	bar.index = -1 // for safety
+	*pq = old[0 : n-1]
+	return bar
+}
+
+// update modifies the priority of an Bar in the queue.
+func (pq *priorityQueue) update(bar *Bar, priority int) {
+	bar.priority = priority
+	heap.Fix(pq, bar.index)
+}
+
+func (pq priorityQueue) maxNumP() int {
+	if pq.Len() == 0 {
+		return 0
+	}
+
+	max := pq[0].NumOfPrependers()
+	for i := 1; i < pq.Len(); i++ {
+		n := pq[i].NumOfPrependers()
+		if n > max {
+			max = n
+		}
+	}
+	return max
+}
+
+func (pq priorityQueue) maxNumA() int {
+	if pq.Len() == 0 {
+		return 0
+	}
+
+	max := pq[0].NumOfAppenders()
+	for i := 1; i < pq.Len(); i++ {
+		n := pq[i].NumOfAppenders()
+		if n > max {
+			max = n
+		}
+	}
+	return max
+}