diff --git a/src/OmniSharp.Abstractions/FileWatching/IFileSystemWatcher.cs b/src/OmniSharp.Abstractions/FileWatching/IFileSystemWatcher.cs
index 9e6f4d0c46..90bccf5196 100644
--- a/src/OmniSharp.Abstractions/FileWatching/IFileSystemWatcher.cs
+++ b/src/OmniSharp.Abstractions/FileWatching/IFileSystemWatcher.cs
@@ -9,8 +9,8 @@ public interface IFileSystemWatcher
         /// <summary>
         /// Call to watch a file or directory path for changes.
         /// </summary>
-        /// <param name="fileOrDirectoryPath">The file or directory path to watch.</param>
+        /// <param name="pathOrExtension">The file path, directory path or file extension to watch.</param>
         /// <param name="callback">The callback that will be invoked when a change occurs in the watched file or directory.</param>
-        void Watch(string fileOrDirectoryPath, FileSystemNotificationCallback callback);
+        void Watch(string pathOrExtension, FileSystemNotificationCallback callback);
     }
 }
diff --git a/src/OmniSharp.Host/FileWatching/ManualFileSystemWatcher.cs b/src/OmniSharp.Host/FileWatching/ManualFileSystemWatcher.cs
index 4c85f97897..531b3ffbab 100644
--- a/src/OmniSharp.Host/FileWatching/ManualFileSystemWatcher.cs
+++ b/src/OmniSharp.Host/FileWatching/ManualFileSystemWatcher.cs
@@ -29,19 +29,26 @@ public void Notify(string filePath, FileChangeType changeType = FileChangeType.U
                 {
                     directoryCallback(filePath, changeType);
                 }
+
+                var extension = Path.GetExtension(filePath);
+                if (!string.IsNullOrEmpty(extension) &&
+                    _callbacks.TryGetValue(extension, out var extensionCallback))
+                {
+                    extensionCallback(filePath, changeType);
+                }
             }
         }
 
-        public void Watch(string fileOrDirectoryPath, FileSystemNotificationCallback callback)
+        public void Watch(string pathOrExtension, FileSystemNotificationCallback callback)
         {
             lock (_gate)
             {
-                if (_callbacks.TryGetValue(fileOrDirectoryPath, out var existingCallback))
+                if (_callbacks.TryGetValue(pathOrExtension, out var existingCallback))
                 {
                     callback = callback + existingCallback;
                 }
 
-                _callbacks[fileOrDirectoryPath] = callback;
+                _callbacks[pathOrExtension] = callback;
             }
         }
     }
diff --git a/tests/OmniSharp.Roslyn.CSharp.Tests/FilesChangedFacts.cs b/tests/OmniSharp.Roslyn.CSharp.Tests/FilesChangedFacts.cs
index 799cfb764f..7e63762e79 100644
--- a/tests/OmniSharp.Roslyn.CSharp.Tests/FilesChangedFacts.cs
+++ b/tests/OmniSharp.Roslyn.CSharp.Tests/FilesChangedFacts.cs
@@ -55,5 +55,22 @@ public void TestMultipleDirectoryWatchers()
                 Assert.True(secondWatcherCalled);
             }
         }
+
+        [Fact]
+        public void TestFileExtensionWatchers()
+        {
+            using (var host = CreateEmptyOmniSharpHost())
+            {
+                var watcher = host.GetExport<IFileSystemWatcher>();
+
+                var extensionWatcherCalled = false;
+                watcher.Watch(".cs", (path, changeType) => { extensionWatcherCalled = true; });
+
+                var handler = GetRequestHandler(host);
+                handler.Handle(new[] { new FilesChangedRequest() { FileName = "FileName.cs", ChangeType = FileChangeType.Create } });
+
+                Assert.True(extensionWatcherCalled);
+            }
+        }
     }
 }