diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index b0bc023d25c5..1689bb58e0d1 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -280,7 +280,7 @@ struct zs_pool {
 struct zspage {
 	struct {
 		unsigned int fullness:FULLNESS_BITS;
-		unsigned int class:CLASS_BITS;
+		unsigned int class:CLASS_BITS + 1;
 		unsigned int isolated:ISOLATED_BITS;
 		unsigned int magic:MAGIC_VAL_BITS;
 	};