diff --git a/sorting/heap_sort.c b/sorting/heap_sort.c
index ba3ddb57..dc901736 100644
--- a/sorting/heap_sort.c
+++ b/sorting/heap_sort.c
@@ -6,6 +6,10 @@ void build_maxheap(int *a, int n);
 
 /**
  * max_heapify takes O(logn).
+ * @param a pointer to array a containing heap elements.
+ * @param i element at which max_heapify needs to be performed.
+ * @param n where n is number of elemnts in array a.
+ * @returns void.
  */
 void max_heapify(int *a, int i, int n)
 {
@@ -44,6 +48,9 @@ void heapsort(int *a, int n)
 
 /**
  * build_maxheap takes O(n).
+ * @param a pointer to array a containing heap elements.
+ * @param n where n is number of elemnts in array a.
+ * @returns void.
  */
 void build_maxheap(int *a, int n)
 {