diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index fb8fbb1650..3c808e2c07 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -688,7 +688,7 @@ int __init make_memory_node(const struct kernel_info *kinfo, int addrcells,
             continue;
 
         nr_cells += reg_size;
-        BUG_ON(nr_cells >= ARRAY_SIZE(reg));
+        BUG_ON(nr_cells > ARRAY_SIZE(reg));
         dt_child_set_range(&cells, addrcells, sizecells, start, size);
     }
 
diff --git a/xen/common/device-tree/static-shmem.c b/xen/common/device-tree/static-shmem.c
index 79f23caa77..4c4cc1b123 100644
--- a/xen/common/device-tree/static-shmem.c
+++ b/xen/common/device-tree/static-shmem.c
@@ -838,7 +838,7 @@ void __init shm_mem_node_fill_reg_range(const struct kernel_info *kinfo,
         paddr_t size = mem->bank[i].size;
 
         *nr_cells += addrcells + sizecells;
-        BUG_ON(*nr_cells >= DT_MEM_NODE_REG_RANGE_SIZE);
+        BUG_ON(*nr_cells > DT_MEM_NODE_REG_RANGE_SIZE);
         dt_child_set_range(&cells, addrcells, sizecells, start, size);
     }
 }