diff --git a/src/algorithms/graph/prim/__test__/prim.test.js b/src/algorithms/graph/prim/__test__/prim.test.js
index 797f5f5b..ac608df8 100644
--- a/src/algorithms/graph/prim/__test__/prim.test.js
+++ b/src/algorithms/graph/prim/__test__/prim.test.js
@@ -55,7 +55,7 @@ describe('prim', () => {
     expect(minimumSpanningTree.getWeight()).toBe(24);
     expect(minimumSpanningTree.getAllVertices().length).toBe(graph.getAllVertices().length);
     expect(minimumSpanningTree.getAllEdges().length).toBe(graph.getAllVertices().length - 1);
-    expect(minimumSpanningTree.toString()).toBe('A,B,D,C,E,F,G');
+    expect(minimumSpanningTree.toString()).toBe('A,B,C,E,D,F,G');
   });
 
   it('should find minimum spanning tree for simple graph', () => {
diff --git a/src/data-structures/heap/Heap.js b/src/data-structures/heap/Heap.js
index b5477716..59ed5f0f 100644
--- a/src/data-structures/heap/Heap.js
+++ b/src/data-structures/heap/Heap.js
@@ -257,9 +257,9 @@ export default class Heap {
         nextIndex = this.getLeftChildIndex(currentIndex);
       }
 
-      if (!this.pairIsInCorrectOrder(
-        this.heapContainer[nextIndex],
+      if (this.pairIsInCorrectOrder(
         this.heapContainer[currentIndex],
+        this.heapContainer[nextIndex],
       )) {
         break;
       }