1 files changed, 8 insertions, 2 deletions
diff --git a/mcs/class/Microsoft.Build/Microsoft.Build.Construction/ProjectPropertyGroupElement.cs b/mcs/class/Microsoft.Build/Microsoft.Build.Construction/ProjectPropertyGroupElement.cs
index 0050ff5fee..4cee2f9d98 100644
--- a/mcs/class/Microsoft.Build/Microsoft.Build.Construction/ProjectPropertyGroupElement.cs
+++ b/mcs/class/Microsoft.Build/Microsoft.Build.Construction/ProjectPropertyGroupElement.cs
@@ -76,9 +76,15 @@ namespace Microsoft.Build.Construction
                         get { return "PropertyGroup"; }
                 }
 
-                internal override ProjectElement LoadChildElement (string name)
+                internal override ProjectElement LoadChildElement (XmlReader reader)
                 {
-                        return AddProperty (name, null);
+                        switch (reader.LocalName) {
+                        case "ItemGroup":
+                        case "PropertyGroup":
+                                throw CreateError (reader, string.Format ("{0} is a reserved name that cannot be used for a property.", reader.LocalName));
+                        // others need to be checked too, but things like "Project" are somehow allowed...
+                        }
+                        return AddProperty (reader.LocalName, null);
                 }
         }
 }