diff --git a/kernel/resource.c b/kernel/resource.c
index 673061c..8957d68 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -511,7 +511,7 @@
  * @newsize: new size of the resource descriptor
  * @constraint: the size and alignment constraints to be met.
  */
-int reallocate_resource(struct resource *root, struct resource *old,
+static int reallocate_resource(struct resource *root, struct resource *old,
 			resource_size_t newsize,
 			struct resource_constraint  *constraint)
 {