diff --git a/include/lmb.h b/include/lmb.h
index 1476d78c28..7298c2ccc4 100644
--- a/include/lmb.h
+++ b/include/lmb.h
@@ -68,7 +68,7 @@ struct lmb_region {
 struct lmb {
 	struct lmb_region memory;
 	struct lmb_region reserved;
-#if IS_ENABLED(CONFIG_LMB_MEMORY_REGIONS)
+#ifdef CONFIG_LMB_MEMORY_REGIONS
 	struct lmb_property memory_regions[CONFIG_LMB_MEMORY_REGIONS];
 	struct lmb_property reserved_regions[CONFIG_LMB_RESERVED_REGIONS];
 #endif
diff --git a/lib/lmb.c b/lib/lmb.c
index f21fe672ae..c599608fa3 100644
--- a/lib/lmb.c
+++ b/lib/lmb.c
@@ -108,7 +108,7 @@ void lmb_init(struct lmb *lmb)
 #if IS_ENABLED(CONFIG_LMB_USE_MAX_REGIONS)
 	lmb->memory.max = CONFIG_LMB_MAX_REGIONS;
 	lmb->reserved.max = CONFIG_LMB_MAX_REGIONS;
-#elif IS_ENABLED(CONFIG_LMB_MEMORY_REGIONS)
+#elif defined(CONFIG_LMB_MEMORY_REGIONS)
 	lmb->memory.max = CONFIG_LMB_MEMORY_REGIONS;
 	lmb->reserved.max = CONFIG_LMB_RESERVED_REGIONS;
 	lmb->memory.region = lmb->memory_regions;