diff --git a/data_structures/binaryheap.cpp b/data_structures/binaryheap.cpp
index 21da4845b..483bd7c02 100644
--- a/data_structures/binaryheap.cpp
+++ b/data_structures/binaryheap.cpp
@@ -22,8 +22,8 @@ class MinHeap {
         harr = new int[cap];
     }
 
-    /** to heapify a subtree with the root at given index
-     */
+    /** to heapify a subtree with the root at given index */
+    void MinHeapify(int);
 
     int parent(int i) { return (i - 1) / 2; }