diff --git a/data_structures/binaryheap.cpp b/data_structures/binaryheap.cpp
index c3a1f5cf6..21da4845b 100644
--- a/data_structures/binaryheap.cpp
+++ b/data_structures/binaryheap.cpp
@@ -24,7 +24,6 @@ class MinHeap {
 
     /** to heapify a subtree with the root at given index
      */
-    void MinHeapify(int);
 
     int parent(int i) { return (i - 1) / 2; }