diff --git a/heap.c b/heap.c
index d58085b..731ae4a 100644
--- a/heap.c
+++ b/heap.c
@@ -36,12 +36,18 @@ void heap_split(mblock_t* block, unsigned int size)
 
 void heap_join(mblock_t* block, mblock_t* other)
 {
-    if (other > block)
+    if (block < other)
     {
         mblock_t* next = (mblock_t*)((uint8_t*)other + other->size);
         next->prev = block;
         block->size += other->size;
     }
+    else if (block > other)
+    {
+        mblock_t* next = (mblock_t*)((uint8_t*)block + block->size);
+        next->prev = other;
+        other->size += block->size;
+    }
 }
 
 int main()