diff --git a/SharpCompress/Archive/ArchiveFactory.cs b/SharpCompress/Archive/ArchiveFactory.cs
index 619c416f..b778b453 100644
--- a/SharpCompress/Archive/ArchiveFactory.cs
+++ b/SharpCompress/Archive/ArchiveFactory.cs
@@ -54,7 +54,7 @@ namespace SharpCompress.Archive
                 stream.Seek(0, SeekOrigin.Begin);
                 return GZipArchive.Open(stream, options);
             }
-            throw new InvalidOperationException("Cannot determine compressed stream type.");
+            throw new InvalidOperationException("Cannot determine compressed stream type.  Supported Archive Formats: Zip, GZip, Tar, Rar, 7Zip");
         }
 
         public static IArchive Create(ArchiveType type)
diff --git a/SharpCompress/Reader/ReaderFactory.cs b/SharpCompress/Reader/ReaderFactory.cs
index 52dbfeab..e336f2cb 100644
--- a/SharpCompress/Reader/ReaderFactory.cs
+++ b/SharpCompress/Reader/ReaderFactory.cs
@@ -74,7 +74,7 @@ namespace SharpCompress.Reader
                 return RarReader.Open(rewindableStream, options);
             }
 
-            throw new InvalidOperationException("Cannot determine compressed stream type.");
+            throw new InvalidOperationException("Cannot determine compressed stream type.  Supported Reader Formats: Zip, GZip, BZip2, Tar, Rar");
         }
     }
 }
\ No newline at end of file