diff --git a/NzbDrone.Api/RootFolders/RootFolderModule.cs b/NzbDrone.Api/RootFolders/RootFolderModule.cs
index 3accd37df..f160570ff 100644
--- a/NzbDrone.Api/RootFolders/RootFolderModule.cs
+++ b/NzbDrone.Api/RootFolders/RootFolderModule.cs
@@ -5,9 +5,9 @@ namespace NzbDrone.Api.RootFolders
 {
     public class RootFolderModule : NzbDroneRestModule<RootFolderResource>
     {
-        private readonly RootFolderService _rootFolderService;
+        private readonly IRootFolderService _rootFolderService;
 
-        public RootFolderModule(RootFolderService rootFolderService)
+        public RootFolderModule(IRootFolderService rootFolderService)
         {
             _rootFolderService = rootFolderService;
 
diff --git a/NzbDrone.Common/NzbDrone.Common.csproj b/NzbDrone.Common/NzbDrone.Common.csproj
index 313cdbc0a..e6d441aa7 100644
--- a/NzbDrone.Common/NzbDrone.Common.csproj
+++ b/NzbDrone.Common/NzbDrone.Common.csproj
@@ -91,6 +91,7 @@
     <Compile Include="Exceptions\NzbDroneException.cs" />
     <Compile Include="Instrumentation\GlobalExceptionHandlers.cs" />
     <Compile Include="Instrumentation\ExceptronTarget.cs" />
+    <Compile Include="PathEqualityComparer.cs" />
     <Compile Include="TPL\LimitedConcurrencyLevelTaskScheduler.cs" />
     <Compile Include="Security\IgnoreCertErrorPolicy.cs" />
     <Compile Include="StringExtensions.cs" />
diff --git a/NzbDrone.Common/PathEqualityComparer.cs b/NzbDrone.Common/PathEqualityComparer.cs
new file mode 100644
index 000000000..c70abb7b7
--- /dev/null
+++ b/NzbDrone.Common/PathEqualityComparer.cs
@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace NzbDrone.Common
+{
+    public class PathEqualityComparer : IEqualityComparer<String>
+    {
+        public bool Equals(string x, string y)
+        {
+            return x.PathEquals(y);
+        }
+
+        public int GetHashCode(string obj)
+        {
+            return obj.CleanFilePath().GetHashCode();
+        }
+    }
+}
diff --git a/NzbDrone.Common/PathExtensions.cs b/NzbDrone.Common/PathExtensions.cs
index 4e7d2251c..15e3b8a08 100644
--- a/NzbDrone.Common/PathExtensions.cs
+++ b/NzbDrone.Common/PathExtensions.cs
@@ -35,11 +35,12 @@ public static string CleanFilePath(this string path)
             return info.FullName.TrimEnd('/').Trim('\\', ' ');
         }
 
-
         public static bool PathEquals(this string firstPath, string secondPath)
         {
-            Ensure.That(() => firstPath).IsValidPath();
-            Ensure.That(() => secondPath).IsValidPath();
+            if (OsInfo.IsLinux)
+            {
+                return String.Equals(firstPath.CleanFilePath(), secondPath.CleanFilePath());
+            }
 
             return String.Equals(firstPath.CleanFilePath(), secondPath.CleanFilePath(), StringComparison.InvariantCultureIgnoreCase);
         }
diff --git a/NzbDrone.Core/RootFolders/RootFolderService.cs b/NzbDrone.Core/RootFolders/RootFolderService.cs
index a27fa01a7..f85a371f6 100644
--- a/NzbDrone.Core/RootFolders/RootFolderService.cs
+++ b/NzbDrone.Core/RootFolders/RootFolderService.cs
@@ -1,4 +1,5 @@
-using System.Linq;
+using System.Diagnostics;
+using System.Linq;
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -40,14 +41,14 @@ public RootFolderService(IBasicRepository<RootFolder> rootFolderRepository,
             _configService = configService;
         }
 
-        public virtual List<RootFolder> All()
+        public List<RootFolder> All()
         {
             var rootFolders = _rootFolderRepository.All().ToList();
 
             return rootFolders;
         }
 
-        public virtual List<RootFolder> AllWithUnmappedFolders()
+        public List<RootFolder> AllWithUnmappedFolders()
         {
             var rootFolders = _rootFolderRepository.All().ToList();
 
@@ -63,7 +64,7 @@ public virtual List<RootFolder> AllWithUnmappedFolders()
             return rootFolders;
         }
 
-        public virtual RootFolder Add(RootFolder rootFolder)
+        public RootFolder Add(RootFolder rootFolder)
         {
             var all = All();
 
@@ -87,12 +88,12 @@ public virtual RootFolder Add(RootFolder rootFolder)
             return rootFolder;
         }
 
-        public virtual void Remove(int id)
+        public void Remove(int id)
         {
             _rootFolderRepository.Delete(id);
         }
 
-        public virtual List<UnmappedFolder> GetUnmappedFolders(string path)
+        public List<UnmappedFolder> GetUnmappedFolders(string path)
         {
             Logger.Debug("Generating list of unmapped folders");
             if (String.IsNullOrEmpty(path))
@@ -107,13 +108,13 @@ public virtual List<UnmappedFolder> GetUnmappedFolders(string path)
                 return results;
             }
 
-            foreach (string seriesFolder in _diskProvider.GetDirectories(path))
+            var seriesFolders = _diskProvider.GetDirectories(path).ToList();
+            var unmappedFolders = seriesFolders.Except(series.Select(s => s.Path), new PathEqualityComparer()).ToList();
+
+            foreach (string unmappedFolder in unmappedFolders)
             {
-                if (!series.Any(s => s.Path.PathEquals(seriesFolder)))
-                {
-                    var di = new DirectoryInfo(seriesFolder.Normalize());
-                    results.Add(new UnmappedFolder { Name = di.Name, Path = di.FullName });
-                }
+                var di = new DirectoryInfo(unmappedFolder.Normalize());
+                results.Add(new UnmappedFolder { Name = di.Name, Path = di.FullName });
             }
 
             if (Path.GetPathRoot(path).Equals(path, StringComparison.InvariantCultureIgnoreCase))
@@ -126,7 +127,7 @@ public virtual List<UnmappedFolder> GetUnmappedFolders(string path)
             return results;
         }
 
-        public virtual Dictionary<string, long> FreeSpaceOnDrives()
+        public Dictionary<string, long> FreeSpaceOnDrives()
         {
             var freeSpace = new Dictionary<string, long>();