diff --git a/src/NzbDrone.Core.Test/MediaFiles/EpisodeImport/Specifications/UpgradeSpecificationFixture.cs b/src/NzbDrone.Core.Test/MediaFiles/EpisodeImport/Specifications/UpgradeSpecificationFixture.cs
index a004a15d8..6520b8f05 100644
--- a/src/NzbDrone.Core.Test/MediaFiles/EpisodeImport/Specifications/UpgradeSpecificationFixture.cs
+++ b/src/NzbDrone.Core.Test/MediaFiles/EpisodeImport/Specifications/UpgradeSpecificationFixture.cs
@@ -11,6 +11,7 @@ using NzbDrone.Core.Languages;
 using NzbDrone.Core.MediaFiles;
 using NzbDrone.Core.MediaFiles.EpisodeImport.Specifications;
 using NzbDrone.Core.Parser.Model;
+using NzbDrone.Core.Profiles;
 using NzbDrone.Core.Profiles.Qualities;
 using NzbDrone.Core.Qualities;
 using NzbDrone.Core.Test.Framework;
@@ -447,5 +448,83 @@ namespace NzbDrone.Core.Test.MediaFiles.EpisodeImport.Specifications
 
             Subject.IsSatisfiedBy(_localEpisode, null).Accepted.Should().BeTrue();
         }
+
+        [Test]
+        public void should_return_true_if_upgrade_to_custom_format_score()
+        {
+            var episodeFileCustomFormats = Builder<CustomFormat>.CreateListOfSize(1).Build().ToList();
+
+            var episodeFile = new EpisodeFile
+            {
+                Quality = new QualityModel(Quality.Bluray1080p)
+            };
+
+            _series.QualityProfile.Value.FormatItems = episodeFileCustomFormats.Select(c => new ProfileFormatItem
+            {
+                Format = c,
+                Score = 10
+            })
+                .ToList();
+
+            Mocker.GetMock<IConfigService>()
+                .Setup(s => s.DownloadPropersAndRepacks)
+                .Returns(ProperDownloadTypes.DoNotPrefer);
+
+            Mocker.GetMock<ICustomFormatCalculationService>()
+                .Setup(s => s.ParseCustomFormat(episodeFile))
+                .Returns(episodeFileCustomFormats);
+
+            _localEpisode.Quality = new QualityModel(Quality.Bluray1080p);
+            _localEpisode.CustomFormats = Builder<CustomFormat>.CreateListOfSize(1).Build().ToList();
+            _localEpisode.CustomFormatScore = 20;
+
+            _localEpisode.Episodes = Builder<Episode>.CreateListOfSize(1)
+                .All()
+                .With(e => e.EpisodeFileId = 1)
+                .With(e => e.EpisodeFile = new LazyLoaded<EpisodeFile>(episodeFile))
+                .Build()
+                .ToList();
+
+            Subject.IsSatisfiedBy(_localEpisode, null).Accepted.Should().BeTrue();
+        }
+
+        [Test]
+        public void should_return_false_if_not_upgrade_to_custom_format_score()
+        {
+            var episodeFileCustomFormats = Builder<CustomFormat>.CreateListOfSize(1).Build().ToList();
+
+            var episodeFile = new EpisodeFile
+            {
+                Quality = new QualityModel(Quality.Bluray1080p)
+            };
+
+            _series.QualityProfile.Value.FormatItems = episodeFileCustomFormats.Select(c => new ProfileFormatItem
+                {
+                    Format = c,
+                    Score = 50
+                })
+                .ToList();
+
+            Mocker.GetMock<IConfigService>()
+                .Setup(s => s.DownloadPropersAndRepacks)
+                .Returns(ProperDownloadTypes.DoNotPrefer);
+
+            Mocker.GetMock<ICustomFormatCalculationService>()
+                .Setup(s => s.ParseCustomFormat(episodeFile))
+                .Returns(episodeFileCustomFormats);
+
+            _localEpisode.Quality = new QualityModel(Quality.Bluray1080p);
+            _localEpisode.CustomFormats = Builder<CustomFormat>.CreateListOfSize(1).Build().ToList();
+            _localEpisode.CustomFormatScore = 20;
+
+            _localEpisode.Episodes = Builder<Episode>.CreateListOfSize(1)
+                .All()
+                .With(e => e.EpisodeFileId = 1)
+                .With(e => e.EpisodeFile = new LazyLoaded<EpisodeFile>(episodeFile))
+                .Build()
+                .ToList();
+
+            Subject.IsSatisfiedBy(_localEpisode, null).Accepted.Should().BeFalse();
+        }
     }
 }
diff --git a/src/NzbDrone.Core/MediaFiles/EpisodeImport/Specifications/UpgradeSpecification.cs b/src/NzbDrone.Core/MediaFiles/EpisodeImport/Specifications/UpgradeSpecification.cs
index 4f1ddaf0e..d961dc8dc 100644
--- a/src/NzbDrone.Core/MediaFiles/EpisodeImport/Specifications/UpgradeSpecification.cs
+++ b/src/NzbDrone.Core/MediaFiles/EpisodeImport/Specifications/UpgradeSpecification.cs
@@ -1,6 +1,6 @@
-using System.Collections.Generic;
 using System.Linq;
 using NLog;
+using NzbDrone.Common.Extensions;
 using NzbDrone.Core.Configuration;
 using NzbDrone.Core.CustomFormats;
 using NzbDrone.Core.DecisionEngine;
@@ -13,22 +13,23 @@ namespace NzbDrone.Core.MediaFiles.EpisodeImport.Specifications
     public class UpgradeSpecification : IImportDecisionEngineSpecification
     {
         private readonly IConfigService _configService;
-        private readonly ICustomFormatCalculationService _customFormatCalculationService;
+        private readonly ICustomFormatCalculationService _formatService;
         private readonly Logger _logger;
 
         public UpgradeSpecification(IConfigService configService,
-                                    ICustomFormatCalculationService customFormatCalculationService,
+                                    ICustomFormatCalculationService formatService,
                                     Logger logger)
         {
             _configService = configService;
-            _customFormatCalculationService = customFormatCalculationService;
+            _formatService = formatService;
             _logger = logger;
         }
 
         public Decision IsSatisfiedBy(LocalEpisode localEpisode, DownloadClientItem downloadClientItem)
         {
             var downloadPropersAndRepacks = _configService.DownloadPropersAndRepacks;
-            var qualityComparer = new QualityModelComparer(localEpisode.Series.QualityProfile);
+            var qualityProfile = localEpisode.Series.QualityProfile.Value;
+            var qualityComparer = new QualityModelComparer(qualityProfile);
 
             foreach (var episode in localEpisode.Episodes.Where(e => e.EpisodeFileId > 0))
             {
@@ -44,13 +45,11 @@ namespace NzbDrone.Core.MediaFiles.EpisodeImport.Specifications
 
                 if (qualityCompare < 0)
                 {
-                    _logger.Debug("This file isn't a quality upgrade for all episodes. New Quality is {0}. Skipping {1}", localEpisode.Quality.Quality, localEpisode.Path);
-                    return Decision.Reject("Not an upgrade for existing episode file(s). New Quality is {0}", localEpisode.Quality.Quality);
+                    _logger.Debug("This file isn't a quality upgrade for all episodes. Existing quality: {0}. New Quality {1}. Skipping {2}", episodeFile.Quality.Quality, localEpisode.Quality.Quality, localEpisode.Path);
+                    return Decision.Reject("Not an upgrade for existing episode file(s). Existing quality: {0}. New Quality {1}.", episodeFile.Quality.Quality, localEpisode.Quality.Quality);
                 }
 
-                // Same quality, is not a language upgrade, propers/repacks are preferred and it is not a revision update
-                // This will allow language upgrades of a lower revision to be imported, which are allowed to be grabbed,
-                // they just don't import automatically.
+                // Same quality, propers/repacks are preferred and it is not a revision update. Reject revision downgrade.
 
                 if (qualityCompare == 0 &&
                     downloadPropersAndRepacks != ProperDownloadTypes.DoNotPrefer &&
@@ -59,6 +58,18 @@ namespace NzbDrone.Core.MediaFiles.EpisodeImport.Specifications
                     _logger.Debug("This file isn't a quality revision upgrade for all episodes. Skipping {0}", localEpisode.Path);
                     return Decision.Reject("Not a quality revision upgrade for existing episode file(s)");
                 }
+
+                var currentFormats = _formatService.ParseCustomFormat(episodeFile);
+                var currentScore = qualityProfile.CalculateCustomFormatScore(currentFormats);
+
+                if (localEpisode.CustomFormatScore < currentScore)
+                {
+                    _logger.Debug("New file's custom formats [{0}] do not improve on [{1}], skipping",
+                        localEpisode.CustomFormats.ConcatToString(),
+                        currentFormats.ConcatToString());
+
+                    return Decision.Reject("Not a Custom Format upgrade for existing episode file(s)");
+                }
             }
 
             return Decision.Accept();