diff --git a/dlls/advapi32/lsa.c b/dlls/advapi32/lsa.c
index 5c3ffc45ab5..fd270ff2744 100644
--- a/dlls/advapi32/lsa.c
+++ b/dlls/advapi32/lsa.c
@@ -405,7 +405,7 @@ NTSTATUS WINAPI LsaLookupNames2( LSA_HANDLE policy, ULONG flags, ULONG count,
 
     /* use maximum domain count */
     if (!(*domains = heap_alloc(sizeof(LSA_REFERENCED_DOMAIN_LIST) + sizeof(LSA_TRUST_INFORMATION)*count +
-                                sid_size_total + domainname_size_total)))
+                                sid_size_total + domainname_size_total*sizeof(WCHAR))))
     {
         heap_free(*sids);
         return STATUS_NO_MEMORY;
@@ -440,6 +440,7 @@ NTSTATUS WINAPI LsaLookupNames2( LSA_HANDLE policy, ULONG flags, ULONG count,
             if (domain_size)
             {
                 domain.Length = domain_size * sizeof(WCHAR);
+                domain.MaximumLength = (domain_size + 1) * sizeof(WCHAR);
                 (*sids)[i].DomainIndex = lsa_reflist_add_domain(*domains, &domain, &domain_data);
             }
         }
diff --git a/dlls/advapi32/tests/lsa.c b/dlls/advapi32/tests/lsa.c
index bffb7c05ff7..b1dcc78142a 100644
--- a/dlls/advapi32/tests/lsa.c
+++ b/dlls/advapi32/tests/lsa.c
@@ -390,6 +390,8 @@ static void test_LsaLookupSids(void)
     {
        ok((char*)list->Domains - (char*)list > 0, "%p, %p\n", list, list->Domains);
        ok((char*)list->Domains[0].Sid - (char*)list->Domains > 0, "%p, %p\n", list->Domains, list->Domains[0].Sid);
+       ok(list->Domains[0].Name.MaximumLength > list->Domains[0].Name.Length, "got %d, %d\n", list->Domains[0].Name.MaximumLength,
+           list->Domains[0].Name.Length);
     }
 
     pLsaFreeMemory(names);