diff --git a/mm/mm_heap/mm_free.c b/mm/mm_heap/mm_free.c
index 013c1551425..19a8a744a1b 100644
--- a/mm/mm_heap/mm_free.c
+++ b/mm/mm_heap/mm_free.c
@@ -102,7 +102,18 @@ void mm_delayfree(FAR struct mm_heap_s *heap, FAR void *mem, bool delay)
 
   nodesize = mm_malloc_size(heap, mem);
 #ifdef CONFIG_MM_FILL_ALLOCATIONS
-  memset(mem, MM_FREE_MAGIC, nodesize);
+#if CONFIG_MM_FREE_DELAYCOUNT_MAX > 0
+  /* If delay free is enabled, a memory node will be freed twice.
+   * The first time is to add the node to the delay list, and the second
+   * time is to actually free the node. Therefore, we only colorize the
+   * memory node the first time, when `delay` is set to true.
+   */
+
+  if (delay)
+#endif
+    {
+      memset(mem, MM_FREE_MAGIC, nodesize);
+    }
 #endif
 
   kasan_poison(mem, nodesize);
diff --git a/mm/tlsf/mm_tlsf.c b/mm/tlsf/mm_tlsf.c
index f97022d4a3f..25040a7e72a 100644
--- a/mm/tlsf/mm_tlsf.c
+++ b/mm/tlsf/mm_tlsf.c
@@ -595,7 +595,18 @@ static void mm_delayfree(FAR struct mm_heap_s *heap, FAR void *mem,
       size_t size = mm_malloc_size(heap, mem);
       UNUSED(size);
 #ifdef CONFIG_MM_FILL_ALLOCATIONS
-      memset(mem, MM_FREE_MAGIC, size);
+#if CONFIG_MM_FREE_DELAYCOUNT_MAX > 0
+  /* If delay free is enabled, a memory node will be freed twice.
+   * The first time is to add the node to the delay list, and the second
+   * time is to actually free the node. Therefore, we only colorize the
+   * memory node the first time, when `delay` is set to true.
+   */
+
+  if (delay)
+#endif
+    {
+      memset(mem, MM_FREE_MAGIC, nodesize);
+    }
 #endif
 
       kasan_poison(mem, size);