diff --git a/ExportDXF/DrawingInfo.cs b/ExportDXF/DrawingInfo.cs
index fd71187..835f467 100644
--- a/ExportDXF/DrawingInfo.cs
+++ b/ExportDXF/DrawingInfo.cs
@@ -30,7 +30,7 @@ namespace ExportDXF
 
         public static DrawingInfo Parse(string input)
         {
-            const string pattern = @"(?<jobNo>[34]\d{3}(-\d+\w{1,2})?)\s?(?<dwgNo>[ABEP]\d+(-\d+|[A-Z])?)";
+            const string pattern = @"(?<jobNo>[34]\d{3}(-\d+\w{1,2})?)\s?(?<dwgNo>[ABEP]\d+(-?(\d+|[A-Z]))?)";
 
             var match = Regex.Match(input, pattern);