diff --git a/osu.Game/Extensions/ModelExtensions.cs b/osu.Game/Extensions/ModelExtensions.cs
index 73a87c7003..f8db5f4e88 100644
--- a/osu.Game/Extensions/ModelExtensions.cs
+++ b/osu.Game/Extensions/ModelExtensions.cs
@@ -137,7 +137,7 @@ namespace osu.Game.Extensions
             return instance.OnlineID.Equals(other.OnlineID);
         }
 
-        private static Regex invalid_filename_chars = new Regex(@"(?!$)[^A-Za-z0-9_()[\]. -]", RegexOptions.Compiled);
+        private static readonly Regex invalid_filename_chars = new Regex(@"(?!$)[^A-Za-z0-9_()[\]. \-]", RegexOptions.Compiled);
 
         /// <summary>
         /// Get a valid filename for use inside a zip file. Avoids backslashes being incorrectly converted to directories.