diff --git a/kernel/resource.c b/kernel/resource.c
index 4089d12..7fec0e4 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -571,7 +571,7 @@
 
 }
 
-void reserve_region_with_split(struct resource *root,
+void __init reserve_region_with_split(struct resource *root,
 		resource_size_t start, resource_size_t end,
 		const char *name)
 {