diff --git a/de4dot.code/renamer/TypeNames.cs b/de4dot.code/renamer/TypeNames.cs
index 82ed6626..41adabc8 100644
--- a/de4dot.code/renamer/TypeNames.cs
+++ b/de4dot.code/renamer/TypeNames.cs
@@ -127,6 +127,8 @@ namespace de4dot.code.renamer {
 		}
 
 		protected static string upperFirst(string s) {
+			if (string.IsNullOrEmpty(s))
+				return string.Empty;
 			return s.Substring(0, 1).ToUpperInvariant() + s.Substring(1);
 		}
 	}
diff --git a/dot10 b/dot10
index d7ccb50d..47d3c156 160000
--- a/dot10
+++ b/dot10
@@ -1 +1 @@
-Subproject commit d7ccb50d4ea85a48c05132dff8ae1e38c4dcbba2
+Subproject commit 47d3c156d6b725cc7d020dfcd8b17a025205985f