diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index 1b14f49345..9e2ff7c800 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -1036,6 +1036,7 @@ static int xen_pt_next_level(bool read_only, unsigned int level,
 {
     lpae_t *entry;
     int ret;
+    mfn_t mfn;
 
     entry = *table + offset;
 
@@ -1053,8 +1054,10 @@ static int xen_pt_next_level(bool read_only, unsigned int level,
     if ( lpae_is_mapping(*entry, level) )
         return XEN_TABLE_SUPER_PAGE;
 
+    mfn = lpae_get_mfn(*entry);
+
     xen_unmap_table(*table);
-    *table = xen_map_table(lpae_get_mfn(*entry));
+    *table = xen_map_table(mfn);
 
     return XEN_TABLE_NORMAL_PAGE;
 }