diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 1aadeb42c5a5..11689e1a2924 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -368,7 +368,7 @@ void __init mem_init(void)
 #ifdef CONFIG_DISCONTIGMEM
 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 #endif
-	max_mapnr = highend_pfn;
+	max_mapnr = highend_pfn ? highend_pfn : max_low_pfn;
 #else
 	max_mapnr = max_low_pfn;
 #endif