diff --git a/src/NzbDrone.Core.Test/ParserTests/HashedReleaseFixture.cs b/src/NzbDrone.Core.Test/ParserTests/HashedReleaseFixture.cs
index 694c031f7..5c62ba81d 100644
--- a/src/NzbDrone.Core.Test/ParserTests/HashedReleaseFixture.cs
+++ b/src/NzbDrone.Core.Test/ParserTests/HashedReleaseFixture.cs
@@ -143,7 +143,14 @@ public class HashedReleaseFixture : CoreTest
                 "Series Title 2019",
                 Quality.WEBDL1080p,
                 "NTb"
-            }
+            },
+            new object[]
+            {
+                @"C:\Test\Fake.Dir.S01E01-Test\11E-20S seires.mkv".AsOsAgnostic(),
+                "series",
+                Quality.HDTV720p,
+                null
+            },
         };
 
         [Test]
diff --git a/src/NzbDrone.Core/Parser/Parser.cs b/src/NzbDrone.Core/Parser/Parser.cs
index 2f8d0edfb..4b81038d0 100644
--- a/src/NzbDrone.Core/Parser/Parser.cs
+++ b/src/NzbDrone.Core/Parser/Parser.cs
@@ -510,7 +510,7 @@ public static class Parser
             };
 
         // Regex to detect whether the title was reversed.
-        private static readonly Regex ReversedTitleRegex = new Regex(@"(?:^|[-._ ])(p027|p0801|\d{2,3}E\d{2}S)[-._ ]", RegexOptions.Compiled);
+        private static readonly Regex ReversedTitleRegex = new Regex(@"(?:^|[-._ ])(p027|p0801|\d{2,3}E-?\d{2}S)[-._ ]", RegexOptions.Compiled);
 
         private static readonly RegexReplace NormalizeRegex = new RegexReplace(@"((?:\b|_)(?<!^)([aà](?!$)|an|the|and|or|of)(?!$)(?:\b|_))|\W|_",
                                                                 string.Empty,