diff --git a/Nuget.config b/Nuget.config
index 0e97909..d81b344 100644
--- a/Nuget.config
+++ b/Nuget.config
@@ -1,8 +1,7 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <configuration>
   <packageSources>
     <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
-    <add key="AspNetCiDev" value="https://www.myget.org/F/aspnetcidev/api/v3/index.json" />
     <add key="XUnitDev" value="https://www.myget.org/F/xunit/api/v3/index.json" />
   </packageSources>  
-</configuration>
\ No newline at end of file
+</configuration>
diff --git a/src/Smidge.Core/Cache/PhysicalFileCacheFileSystem.cs b/src/Smidge.Core/Cache/PhysicalFileCacheFileSystem.cs
index dfc8070..bb86729 100644
--- a/src/Smidge.Core/Cache/PhysicalFileCacheFileSystem.cs
+++ b/src/Smidge.Core/Cache/PhysicalFileCacheFileSystem.cs
@@ -1,5 +1,6 @@
-using Microsoft.Extensions.FileProviders;
+using Microsoft.Extensions.FileProviders;
 using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
 using Smidge.Hashing;
 using Smidge.Models;
 using System;
@@ -13,7 +14,8 @@ public class PhysicalFileCacheFileSystem : ICacheFileSystem
         public static PhysicalFileCacheFileSystem CreatePhysicalFileCacheFileSystem(
             IHasher hasher,
             ISmidgeConfig config,
-            IHostEnvironment hosting)
+            IHostEnvironment hosting,
+            ILogger logger)
         {
             var cacheFolder = Path.Combine(hosting.ContentRootPath, config.DataFolder, "Cache", Environment.MachineName.ReplaceNonAlphanumericChars('-'));
 
@@ -22,18 +24,21 @@ public static PhysicalFileCacheFileSystem CreatePhysicalFileCacheFileSystem(
 
             var cacheFileProvider = new PhysicalFileProvider(cacheFolder);
 
-            return new PhysicalFileCacheFileSystem(cacheFileProvider, hasher);
+            return new PhysicalFileCacheFileSystem(cacheFileProvider, hasher, logger);
         }
 
         private readonly IHasher _hasher;
         private readonly PhysicalFileProvider _fileProvider;
+        private readonly ILogger _logger;
 
         public PhysicalFileCacheFileSystem(
             PhysicalFileProvider cacheFileProvider, 
-            IHasher hasher)
+            IHasher hasher,
+            ILogger logger)
         {
             _fileProvider = cacheFileProvider;
             _hasher = hasher;
+            _logger = logger;
         }
 
         public IFileInfo GetRequiredFileInfo(string filePath)
@@ -42,7 +47,7 @@ public IFileInfo GetRequiredFileInfo(string filePath)
 
             if (!fileInfo.Exists)
             {
-                throw new FileNotFoundException($"No such file exists {fileInfo.PhysicalPath ?? fileInfo.Name} (mapped from {filePath})", fileInfo.PhysicalPath ?? fileInfo.Name);
+                _logger.LogError("No such file exists {FileName} (mapped from {FilePath})", fileInfo.PhysicalPath ?? fileInfo.Name, filePath);
             }
 
             return fileInfo;
diff --git a/src/Smidge.Core/FileProcessors/CssImportProcessor.cs b/src/Smidge.Core/FileProcessors/CssImportProcessor.cs
index 245a69e..d7a24cb 100644
--- a/src/Smidge.Core/FileProcessors/CssImportProcessor.cs
+++ b/src/Smidge.Core/FileProcessors/CssImportProcessor.cs
@@ -1,6 +1,7 @@
-using Smidge.Models;
+using Smidge.Models;
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 using System.Text;
 using System.Text.RegularExpressions;
@@ -48,6 +49,12 @@ public async Task ProcessAsync(FileProcessContext fileProcessContext, PreProcess
                 {
                     //it's internal (in theory)
                     var filePath = _fileSystem.GetRequiredFileInfo(path);
+
+                    if (!filePath.Exists)
+                    {
+                        throw new FileNotFoundException(filePath.PhysicalPath ?? filePath.Name);
+                    }
+
                     var content = await _fileSystem.ReadContentsAsync(filePath);
 
                     //This needs to be put back through the whole pre-processor pipeline before being added,
@@ -126,4 +133,4 @@ internal string ParseImportStatements(string content, out IEnumerable<string> im
 
         
     }
-}
\ No newline at end of file
+}
diff --git a/src/Smidge.Core/FileProcessors/PreProcessManager.cs b/src/Smidge.Core/FileProcessors/PreProcessManager.cs
index 5d6f8fb..595b345 100644
--- a/src/Smidge.Core/FileProcessors/PreProcessManager.cs
+++ b/src/Smidge.Core/FileProcessors/PreProcessManager.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Diagnostics;
 using System.IO;
 using System.Threading;
@@ -76,7 +76,17 @@ private async Task ProcessFileImpl(IWebFile file, BundleOptions bundleOptions, B
             var cacheBusterValue = bundleContext.CacheBusterValue;
 
             //we're making this lazy since we don't always want to resolve it
-            var sourceFile = new Lazy<IFileInfo>(() => _fileSystem.GetRequiredFileInfo(file), LazyThreadSafetyMode.None);
+            var sourceFile = new Lazy<IFileInfo>(() =>
+            {
+                var fileInfo = _fileSystem.GetRequiredFileInfo(file);
+
+                if (!fileInfo.Exists)
+                {
+                    throw new FileNotFoundException(fileInfo.PhysicalPath ?? fileInfo.Name);
+                }
+
+                return fileInfo;
+            }, LazyThreadSafetyMode.None);
 
             var cacheFile = _fileSystem.CacheFileSystem.GetCacheFile(file, () => sourceFile.Value, fileWatchEnabled, extension, cacheBusterValue, out var filePath);
 
@@ -127,4 +137,4 @@ private static void FileModified(WatchedFile file)
             file.BundleOptions.FileWatchOptions.Changed(new FileWatchEventArgs(file));
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/Smidge.Core/ISmidgeFileSystem.cs b/src/Smidge.Core/ISmidgeFileSystem.cs
index 2ec7003..2374fba 100644
--- a/src/Smidge.Core/ISmidgeFileSystem.cs
+++ b/src/Smidge.Core/ISmidgeFileSystem.cs
@@ -21,17 +21,17 @@ public interface ISmidgeFileSystem
         /// <param name="webfile"></param>
         /// <returns></returns>
         /// <remarks>
-        /// Throws an exception if the file doesn't exist
+        /// Returns even if the file doesn't exist
         /// </remarks>
         IFileInfo GetRequiredFileInfo(IWebFile webfile);
 
         /// <summary>
         /// Get a required <see cref="IFileInfo"/>
         /// </summary>
-        /// <param name="webfile"></param>
+        /// <param name="filePath"></param>
         /// <returns></returns>
         /// <remarks>
-        /// Throws an exception if the file doesn't exist
+        /// Returns even if the file doesn't exist
         /// </remarks>
         IFileInfo GetRequiredFileInfo(string filePath);
 
diff --git a/src/Smidge.Core/SmidgeFileSystem.cs b/src/Smidge.Core/SmidgeFileSystem.cs
index 041a68e..7e2bf09 100644
--- a/src/Smidge.Core/SmidgeFileSystem.cs
+++ b/src/Smidge.Core/SmidgeFileSystem.cs
@@ -8,6 +8,7 @@
 using Smidge.Options;
 using Smidge.Cache;
 using System.Linq;
+using Microsoft.Extensions.Logging;
 
 namespace Smidge
 {
@@ -21,17 +22,20 @@ public sealed class SmidgeFileSystem : ISmidgeFileSystem
         private readonly IWebsiteInfo _siteInfo;
         private readonly IFileProvider _sourceFileProvider;
         private readonly IFileProviderFilter _fileProviderFilter;
+        private readonly ILogger _logger;
 
         public SmidgeFileSystem(
             IFileProvider sourceFileProvider,
             IFileProviderFilter fileProviderFilter,
             ICacheFileSystem cacheFileProvider,
-            IWebsiteInfo siteInfo)
+            IWebsiteInfo siteInfo,
+            ILogger logger)
         {
             _sourceFileProvider = sourceFileProvider;
             _fileProviderFilter = fileProviderFilter;
             CacheFileSystem = cacheFileProvider;
             _siteInfo = siteInfo;
+            _logger = logger;
         }
 
         public ICacheFileSystem CacheFileSystem { get; }
@@ -43,7 +47,7 @@ public IFileInfo GetRequiredFileInfo(IWebFile webfile)
 
             if (!fileInfo.Exists)
             {
-                throw new FileNotFoundException($"No such file exists {fileInfo.PhysicalPath ?? fileInfo.Name} (mapped from {path})", fileInfo.PhysicalPath ?? fileInfo.Name);
+                _logger.LogError("No such file exists {FileName} (mapped from {FilePath})", fileInfo.PhysicalPath ?? fileInfo.Name, path);
             }
 
             return fileInfo;
@@ -56,7 +60,7 @@ public IFileInfo GetRequiredFileInfo(string filePath)
 
             if (!fileInfo.Exists)
             {
-                throw new FileNotFoundException($"No such file exists {fileInfo.PhysicalPath ?? fileInfo.Name} (mapped from {filePath})", fileInfo.PhysicalPath ?? fileInfo.Name);
+                _logger.LogError("No such file exists {FileName} (mapped from {FilePath})", fileInfo.PhysicalPath ?? fileInfo.Name, filePath);
             }
 
             return fileInfo;
diff --git a/src/Smidge.InMemory/ConfiguredCacheFileSystem.cs b/src/Smidge.InMemory/ConfiguredCacheFileSystem.cs
index 219b220..e438bea 100644
--- a/src/Smidge.InMemory/ConfiguredCacheFileSystem.cs
+++ b/src/Smidge.InMemory/ConfiguredCacheFileSystem.cs
@@ -1,4 +1,4 @@
-using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.FileProviders;
 using Microsoft.Extensions.Hosting;
@@ -10,6 +10,7 @@
 using System;
 using System.IO;
 using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
 
 namespace Smidge.InMemory
 {
@@ -31,14 +32,19 @@ public ConfiguredCacheFileSystem(IOptions<SmidgeOptions> options, IServiceProvid
 
             if (_options.CacheOptions.UseInMemoryCache)
             {
-                _wrapped = new MemoryCacheFileSystem(hasher);
+                var logger = services.GetRequiredService<ILogger<MemoryCacheFileSystem>>();
+
+                _wrapped = new MemoryCacheFileSystem(hasher, logger);
             }
             else
             {
+                var logger = services.GetRequiredService<ILogger<PhysicalFileCacheFileSystem>>();
+
                 _wrapped = PhysicalFileCacheFileSystem.CreatePhysicalFileCacheFileSystem(
                     hasher,
                     services.GetRequiredService<ISmidgeConfig>(),
-                    services.GetRequiredService<IHostEnvironment>());
+                    services.GetRequiredService<IHostEnvironment>(),
+                    logger);
             }
         }
 
diff --git a/src/Smidge.InMemory/MemoryCacheFileSystem.cs b/src/Smidge.InMemory/MemoryCacheFileSystem.cs
index 38783f2..485827d 100644
--- a/src/Smidge.InMemory/MemoryCacheFileSystem.cs
+++ b/src/Smidge.InMemory/MemoryCacheFileSystem.cs
@@ -1,7 +1,8 @@
-using Dazinator.Extensions.FileProviders;
+using Dazinator.Extensions.FileProviders;
 using Dazinator.Extensions.FileProviders.InMemory;
 using Dazinator.Extensions.FileProviders.InMemory.Directory;
 using Microsoft.Extensions.FileProviders;
+using Microsoft.Extensions.Logging;
 using Smidge.Cache;
 using Smidge.Hashing;
 using Smidge.Models;
@@ -17,12 +18,14 @@ public class MemoryCacheFileSystem : ICacheFileSystem
         private readonly IDirectory _directory;
         private readonly IHasher _hasher;
         private readonly IFileProvider _fileProvider;
+        private readonly ILogger _logger;
 
-        public MemoryCacheFileSystem(IHasher hasher)
+        public MemoryCacheFileSystem(IHasher hasher, ILogger logger)
         {
             _directory = new InMemoryDirectory();
             _fileProvider = new InMemoryFileProvider(_directory);
             _hasher = hasher;
+            _logger = logger;
         }
 
         public IFileInfo GetRequiredFileInfo(string filePath)
@@ -31,7 +34,7 @@ public IFileInfo GetRequiredFileInfo(string filePath)
 
             if (!fileInfo.Exists)
             {
-                throw new FileNotFoundException($"No such file exists {fileInfo.PhysicalPath ?? fileInfo.Name} (mapped from {filePath})", fileInfo.PhysicalPath ?? fileInfo.Name);
+                _logger.LogError("No such file exists {FileName} (mapped from {FilePath})", fileInfo.PhysicalPath ?? fileInfo.Name, filePath);
             }
 
             return fileInfo;
diff --git a/src/Smidge/SmidgeStartup.cs b/src/Smidge/SmidgeStartup.cs
index 81249e9..533e11a 100644
--- a/src/Smidge/SmidgeStartup.cs
+++ b/src/Smidge/SmidgeStartup.cs
@@ -1,4 +1,4 @@
-using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc.Infrastructure;
@@ -17,6 +17,7 @@
 using System;
 using System.Collections.Generic;
 using System.Runtime.CompilerServices;
+using Microsoft.Extensions.Logging;
 
 [assembly: InternalsVisibleTo("Smidge.Tests")]
 
@@ -47,6 +48,7 @@ public static IServiceCollection AddSmidge(this IServiceCollection services, ICo
             services.AddSingleton<ISmidgeFileSystem>(p =>
             {
                 var hosting = p.GetRequiredService<IWebHostEnvironment>();
+                var logger = p.GetRequiredService<ILogger<SmidgeFileSystem>>();
 
                 //resolve the ISmidgeFileProvider if there is one
                 var provider = p.GetService<ISmidgeFileProvider>() ?? hosting.WebRootFileProvider;
@@ -54,13 +56,15 @@ public static IServiceCollection AddSmidge(this IServiceCollection services, ICo
                     provider,
                     p.GetRequiredService<IFileProviderFilter>(),
                     p.GetRequiredService<ICacheFileSystem>(),
-                    p.GetRequiredService<IWebsiteInfo>());
+                    p.GetRequiredService<IWebsiteInfo>(),
+                    logger);
             });
             
             services.AddSingleton<ICacheFileSystem>(p => PhysicalFileCacheFileSystem.CreatePhysicalFileCacheFileSystem(
                 p.GetRequiredService<IHasher>(),
                 p.GetRequiredService<ISmidgeConfig>(),
-                p.GetRequiredService<IHostEnvironment>()));
+                p.GetRequiredService<IHostEnvironment>(),
+                p.GetRequiredService<ILogger<PhysicalFileCacheFileSystem>>()));
 
             services.AddSingleton<ISmidgeConfig>((p) =>
             {
diff --git a/test/Smidge.Tests/BundleFileSetGeneratorTests.cs b/test/Smidge.Tests/BundleFileSetGeneratorTests.cs
index dcfb645..9f451bd 100644
--- a/test/Smidge.Tests/BundleFileSetGeneratorTests.cs
+++ b/test/Smidge.Tests/BundleFileSetGeneratorTests.cs
@@ -9,6 +9,7 @@
 using Smidge.Hashing;
 using Smidge.Options;
 using System.Linq;
+using Microsoft.Extensions.Logging;
 using Smidge.FileProcessors;
 using Microsoft.Extensions.Options;
 using Smidge.Cache;
@@ -28,9 +29,10 @@ public void Get_Ordered_File_Set_No_Duplicates()
 
             var fileProvider = new Mock<IFileProvider>();
             var cacheProvider = new Mock<ICacheFileSystem>();
+            var logger = new Mock<ILogger>();
             var fileProviderFilter = new DefaultFileProviderFilter();
 
-            var fileSystemHelper = new SmidgeFileSystem(fileProvider.Object, fileProviderFilter, cacheProvider.Object, Mock.Of<IWebsiteInfo>());
+            var fileSystemHelper = new SmidgeFileSystem(fileProvider.Object, fileProviderFilter, cacheProvider.Object, Mock.Of<IWebsiteInfo>(), logger.Object);
             var pipeline = new PreProcessPipeline(Enumerable.Empty<IPreProcessor>());
             var smidgeOptions = new Mock<IOptions<SmidgeOptions>>();
             smidgeOptions.Setup(opt => opt.Value).Returns(new SmidgeOptions());
@@ -58,9 +60,10 @@ public void Get_Ordered_File_External_Set()
 
             var fileProvider = new Mock<IFileProvider>();
             var cacheProvider = new Mock<ICacheFileSystem>();
+            var logger = new Mock<ILogger>();
             var fileProviderFilter = new DefaultFileProviderFilter();
 
-            var fileSystemHelper = new SmidgeFileSystem(fileProvider.Object, fileProviderFilter, cacheProvider.Object, Mock.Of<IWebsiteInfo>());
+            var fileSystemHelper = new SmidgeFileSystem(fileProvider.Object, fileProviderFilter, cacheProvider.Object, Mock.Of<IWebsiteInfo>(), logger.Object);
             var pipeline = new PreProcessPipeline(Enumerable.Empty<IPreProcessor>());
             var smidgeOptions = new Mock<IOptions<SmidgeOptions>>();
             smidgeOptions.Setup(opt => opt.Value).Returns(new SmidgeOptions());
@@ -89,9 +92,10 @@ public void Get_Ordered_File_Set_Correct_Order()
 
             var fileProvider = new Mock<IFileProvider>();
             var cacheProvider = new Mock<ICacheFileSystem>();
+            var logger = new Mock<ILogger>();
             var fileProviderFilter = new DefaultFileProviderFilter();
 
-            var fileSystemHelper = new SmidgeFileSystem(fileProvider.Object, fileProviderFilter, cacheProvider.Object, Mock.Of<IWebsiteInfo>());
+            var fileSystemHelper = new SmidgeFileSystem(fileProvider.Object, fileProviderFilter, cacheProvider.Object, Mock.Of<IWebsiteInfo>(), logger.Object);
             var pipeline = new PreProcessPipeline(Enumerable.Empty<IPreProcessor>());
             var smidgeOptions = new Mock<IOptions<SmidgeOptions>>();
             smidgeOptions.Setup(opt => opt.Value).Returns(new SmidgeOptions());
diff --git a/test/Smidge.Tests/CssImportProcessorTests.cs b/test/Smidge.Tests/CssImportProcessorTests.cs
index d755721..333fcb3 100644
--- a/test/Smidge.Tests/CssImportProcessorTests.cs
+++ b/test/Smidge.Tests/CssImportProcessorTests.cs
@@ -1,5 +1,6 @@
-using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.FileProviders;
+using Microsoft.Extensions.Logging;
 using Moq;
 using Smidge.Cache;
 using Smidge.FileProcessors;
@@ -69,7 +70,8 @@ private ISmidgeFileSystem GetFileSystem()
                 Mock.Of<IFileProvider>(),
                 Mock.Of<IFileProviderFilter>(),
                 Mock.Of<ICacheFileSystem>(),
-                Mock.Of<IWebsiteInfo>());
+                Mock.Of<IWebsiteInfo>(),
+                Mock.Of<ILogger>());
             return fileSystem;
         }
 
@@ -81,4 +83,4 @@ private IWebsiteInfo GetWebsiteInfo()
             return websiteInfo.Object;
         }
     }
-}
\ No newline at end of file
+}
diff --git a/test/Smidge.Tests/FileBatcherTests.cs b/test/Smidge.Tests/FileBatcherTests.cs
index b4d9e57..d889aa9 100644
--- a/test/Smidge.Tests/FileBatcherTests.cs
+++ b/test/Smidge.Tests/FileBatcherTests.cs
@@ -9,6 +9,7 @@
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Mvc.Infrastructure;
 using Microsoft.Extensions.FileProviders;
+using Microsoft.Extensions.Logging;
 using Xunit;
 using Smidge.Hashing;
 using Smidge.Cache;
@@ -28,10 +29,11 @@ public void Get_Composite_File_Collection_For_Url_Generation_No_Duplicates()
 
             var fileProvider = new Mock<IFileProvider>();
             var cacheProvider = new Mock<ICacheFileSystem>();
+            var logger = new Mock<ILogger>();
             var fileProviderFilter = new DefaultFileProviderFilter();
 
             var hasher = Mock.Of<IHasher>();
-            var fileSystemHelper = new SmidgeFileSystem(fileProvider.Object, fileProviderFilter, cacheProvider.Object, Mock.Of<IWebsiteInfo>());
+            var fileSystemHelper = new SmidgeFileSystem(fileProvider.Object, fileProviderFilter, cacheProvider.Object, Mock.Of<IWebsiteInfo>(), logger.Object);
             var batcher = new FileBatcher(fileSystemHelper, urlHelper, hasher);
 
             var file = new Mock<IFileInfo>();
@@ -59,9 +61,10 @@ public void Get_Composite_File_Collection_For_Url_Generation()
 
             var fileProvider = new Mock<IFileProvider>();
             var cacheProvider = new Mock<ICacheFileSystem>();
+            var logger = new Mock<ILogger>();
             var fileProviderFilter = new DefaultFileProviderFilter();
             var hasher = Mock.Of<IHasher>();
-            var fileSystemHelper = new SmidgeFileSystem(fileProvider.Object, fileProviderFilter, cacheProvider.Object, Mock.Of<IWebsiteInfo>());          
+            var fileSystemHelper = new SmidgeFileSystem(fileProvider.Object, fileProviderFilter, cacheProvider.Object, Mock.Of<IWebsiteInfo>(), logger.Object);          
             var batcher = new FileBatcher(fileSystemHelper, urlHelper, hasher);
 
             var file = new Mock<IFileInfo>();
diff --git a/test/Smidge.Tests/SmidgeFileSystemTests.cs b/test/Smidge.Tests/SmidgeFileSystemTests.cs
index c5878c8..304e0f1 100644
--- a/test/Smidge.Tests/SmidgeFileSystemTests.cs
+++ b/test/Smidge.Tests/SmidgeFileSystemTests.cs
@@ -3,19 +3,22 @@
 using System.IO;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.FileProviders;
+using Microsoft.Extensions.Logging;
 using Xunit;
 using Smidge.Cache;
+using System.Collections.Generic;
 
 namespace Smidge.Tests
 {
     public class SmidgeFileSystemTests
     {
-        private ISmidgeFileSystem Create(IWebsiteInfo websiteInfo, string url = "~/Js/Test1.js")
+        private ISmidgeFileSystem Create(IWebsiteInfo websiteInfo, out Mock<ILogger> logger, string url = "~/Js/Test1.js")
         {
             var webRootPath = $"C:{Path.DirectorySeparatorChar}MySolution{Path.DirectorySeparatorChar}MyProject";
 
             var cacheProvider = new Mock<ICacheFileSystem>();
             var fileProvider = new Mock<IFileProvider>();
+            logger = new Mock<ILogger>();
             var fileProviderFilter = new DefaultFileProviderFilter();
             var file = new Mock<IFileInfo>();
             string filePath = Path.Combine(webRootPath, $"Js{Path.DirectorySeparatorChar}Test1.js");
@@ -33,7 +36,8 @@ private ISmidgeFileSystem Create(IWebsiteInfo websiteInfo, string url = "~/Js/Te
                 fileProvider.Object,
                 fileProviderFilter,
                 cacheProvider.Object,
-                websiteInfo);
+                websiteInfo,
+                logger.Object);
 
 
             return helper;
@@ -55,7 +59,7 @@ public void ConvertToFileProviderPath(string from, string to, string pathBase)
             {
                 websiteInfo.Setup(x => x.GetBasePath()).Returns(pathBase);
             }
-            var fs = Create(websiteInfo.Object);
+            var fs = Create(websiteInfo.Object, out _);
 
             var result = fs.ConvertToFileProviderPath(from);
 
@@ -63,7 +67,7 @@ public void ConvertToFileProviderPath(string from, string to, string pathBase)
         }
 
         [Fact]
-        public void Get_File_Info_Non_Existent_File_Throws_Informative_Exception()
+        public void Get_File_Info_Non_Existent_File_Logs_Informative_Error()
         {
             var url = "~/Js/Test1.js";
 
@@ -71,13 +75,19 @@ public void Get_File_Info_Non_Existent_File_Throws_Informative_Exception()
             websiteInfo.Setup(x => x.GetBasePath()).Returns(string.Empty);
             websiteInfo.Setup(x => x.GetBaseUrl()).Returns(new Uri("http://test.com"));
 
-            var helper = Create(websiteInfo.Object, url);
+            var helper = Create(websiteInfo.Object, out var logger, url);
 
-            FileNotFoundException ex = Assert.Throws<FileNotFoundException>(() => helper.GetRequiredFileInfo(url));
+            helper.GetRequiredFileInfo(url);
 
-            //    var result = helper.MapPath(url);
-
-            Assert.Contains(url, ex.Message);
+            logger.Verify(
+                x => x.Log(
+                    LogLevel.Error,
+                    0,
+                    It.Is<It.IsAnyType>((v, t) => v.ToString().Contains(url)),
+                    null,
+                    It.IsAny<Func<It.IsAnyType, Exception, string>>()
+                )
+            );
         }
 
         [Fact]
@@ -95,6 +105,7 @@ public void Reverse_Map_Path()
 
             var urlHelper = new Mock<IUrlHelper>();
             var cacheProvider = new Mock<ICacheFileSystem>();
+            var logger = new Mock<Microsoft.Extensions.Logging.ILogger>();
             var fileProvider = new Mock<IFileProvider>();
             var fileProviderFilter = new DefaultFileProviderFilter();
 
@@ -103,7 +114,8 @@ public void Reverse_Map_Path()
                 fileProvider.Object,
                 fileProviderFilter,
                 cacheProvider.Object,
-                Mock.Of<IWebsiteInfo>());
+                Mock.Of<IWebsiteInfo>(),
+                logger.Object);
 
             var result = helper.ReverseMapPath(subPath, file.Object);
 
diff --git a/test/Smidge.Tests/SmidgeHelperTests.cs b/test/Smidge.Tests/SmidgeHelperTests.cs
index 71ff88d..77a4620 100644
--- a/test/Smidge.Tests/SmidgeHelperTests.cs
+++ b/test/Smidge.Tests/SmidgeHelperTests.cs
@@ -23,6 +23,7 @@ public class SmidgeHelperTests
         private readonly IUrlManager _urlManager = Mock.Of<IUrlManager>();
         private readonly IFileProvider _fileProvider = Mock.Of<IFileProvider>();
         private readonly ICacheFileSystem _cacheProvider = Mock.Of<ICacheFileSystem>();
+        private readonly ILogger _logger = Mock.Of<ILogger>();
         private readonly IFileProviderFilter _fileProviderFilter = Mock.Of<IFileProviderFilter>();
         private readonly IHasher _hasher = Mock.Of<IHasher>();
         private readonly IEnumerable<IPreProcessor> _preProcessors = new List<IPreProcessor>();
@@ -46,7 +47,7 @@ public SmidgeHelperTests()
             _httpContextAccessor.Setup(x => x.HttpContext).Returns(_httpContext.Object);
 
             _dynamicallyRegisteredWebFiles = new DynamicallyRegisteredWebFiles();
-            _fileSystemHelper = new SmidgeFileSystem(_fileProvider, _fileProviderFilter, _cacheProvider, Mock.Of<IWebsiteInfo>());
+            _fileSystemHelper = new SmidgeFileSystem(_fileProvider, _fileProviderFilter, _cacheProvider, Mock.Of<IWebsiteInfo>(), _logger);
             _smidgeOptions = new Mock<IOptions<SmidgeOptions>>();
             _smidgeOptions.Setup(opt => opt.Value).Returns(new SmidgeOptions
             {