diff --git a/BeWo/ViewModel/WohneinheitVM.cs b/BeWo/ViewModel/WohneinheitVM.cs
index 171e85c11..00f68e5f9 100644
--- a/BeWo/ViewModel/WohneinheitVM.cs
+++ b/BeWo/ViewModel/WohneinheitVM.cs
@@ -287,12 +287,12 @@ namespace BeWo.ViewModel
             if (vm2 is null)
                 return -1;
 
-            var compare1 = vm1.Wohnname.CompareTo(vm2.Wohnname);
+            var compare1 = string.Compare(vm1.Wohnname, vm2.Wohnname);
 
             if (compare1 != 0)
                 return compare1;
 
-            var compare2 = vm1.Zimmername.CompareTo(vm2.Zimmername);
+            var compare2 = string.Compare(vm1.Zimmername, vm2.Zimmername);
 
             return compare2;
         }