diff --git a/src/system/kernel/heap.cpp b/src/system/kernel/heap.cpp
index 42ff5a0354..d96f0ddac8 100644
--- a/src/system/kernel/heap.cpp
+++ b/src/system/kernel/heap.cpp
@@ -1912,6 +1912,15 @@ heap_init(addr_t base, size_t size)
 status_t
 heap_init_post_sem()
 {
+#if PARANOID_KERNEL_MALLOC
+	vm_block_address_range("uninitialized heap memory",
+		(void *)ROUNDDOWN(0xcccccccc, B_PAGE_SIZE), B_PAGE_SIZE * 64);
+#endif
+#if PARANOID_KERNEL_FREE
+	vm_block_address_range("freed heap memory",
+		(void *)ROUNDDOWN(0xdeadbeef, B_PAGE_SIZE), B_PAGE_SIZE * 64);
+#endif
+
 	sHeapGrowSem = create_sem(0, "heap_grow_sem");
 	if (sHeapGrowSem < 0) {
 		panic("heap_init_post_sem(): failed to create heap grow sem\n");