diff --git a/kernel/heap/src/lib.rs b/kernel/heap/src/lib.rs
index d5e9700d1c..9d93a8336a 100644
--- a/kernel/heap/src/lib.rs
+++ b/kernel/heap/src/lib.rs
@@ -89,7 +89,7 @@ unsafe impl GlobalAlloc for Heap {
     }
 
     unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
-        if (ptr as usize) < INITIAL_HEAP_END_ADDR {
+        if KERNEL_HEAP_START <= (ptr as usize) && (ptr as usize) < INITIAL_HEAP_END_ADDR {
             self.initial_allocator.lock().deallocate(ptr, layout);
         }
         else {