diff --git a/mm/sparse.c b/mm/sparse.c
index 8ffc089..5d9dbbb 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -377,7 +377,7 @@
 }
 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
 
-struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
+static struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
 {
 	struct page *map;
 	struct mem_section *ms = __nr_to_section(pnum);