diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c
index dcd46873c78bfaa1f15fb6ff3aec4a108a6df13a..ea2b0c588f9b9cfa996a3e570989c08c7b80dd5a 100644
--- a/src/libxl/libxl_conf.c
+++ b/src/libxl/libxl_conf.c
@@ -367,6 +367,10 @@ libxlMakeDomBuildInfo(virDomainDefPtr def,
     }
 
     b_info->sched_params.weight = 1000;
+    /* Xen requires the memory sizes to be rounded to 1MiB increments */
+    virDomainDefSetMemoryTotal(def,
+                               VIR_ROUND_UP(virDomainDefGetMemoryInitial(def), 1024));
+    def->mem.cur_balloon = VIR_ROUND_UP(def->mem.cur_balloon, 1024);
     b_info->max_memkb = virDomainDefGetMemoryInitial(def);
     b_info->target_memkb = def->mem.cur_balloon;
     if (hvm) {