diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 21123b8ee4d4..a1ebaecc8122 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -392,6 +392,8 @@ static void __unflatten_device_tree(struct boot_param_header *blob,
 	mem = (unsigned long)
 		dt_alloc(size + 4, __alignof__(struct device_node));
 
+	memset((void *)mem, 0, size);
+
 	((__be32 *)mem)[size / 4] = cpu_to_be32(0xdeadbeef);
 
 	pr_debug("  unflattening %lx...\n", mem);