diff --git a/include/asm-generic/kmap_types.h b/include/asm-generic/kmap_types.h
index 97e807c8c8124bd0ba48dfca9ae2b1461d0d7677..0232ccb76f2b18d86b15992c3c6afa45c83a3340 100644
--- a/include/asm-generic/kmap_types.h
+++ b/include/asm-generic/kmap_types.h
@@ -29,6 +29,9 @@ KMAP_D(16)	KM_IRQ_PTE,
 KMAP_D(17)	KM_NMI,
 KMAP_D(18)	KM_NMI_PTE,
 KMAP_D(19)	KM_KDB,
+/*
+ * Remember to update debug_kmap_atomic() when adding new kmap types!
+ */
 KMAP_D(20)	KM_TYPE_NR
 };