diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,11 @@
 Changes
 =======
 
+Version 0.4.4.0
+----------
+* Use hinotify and -DHAVE_NATIVE_WATCHER for FreeBSD (#121)
+* Start testing FreeBSD in CI (#122)
+
 Version 0.4.3.0
 ----------
 * Use polling as a generic fallback and add support for WASM (https://github.com/haskell-fswatch/hfsnotify/pull/110)
diff --git a/fsnotify.cabal b/fsnotify.cabal
--- a/fsnotify.cabal
+++ b/fsnotify.cabal
@@ -5,7 +5,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           fsnotify
-version:        0.4.3.0
+version:        0.4.4.0
 synopsis:       Cross platform library for file change notification.
 description:    Cross platform library for file creation, modification, and deletion notification. This library builds upon existing libraries for platform-specific Windows, Mac, and Linux filesystem event notification.
 category:       Filesystem
@@ -48,13 +48,9 @@
     , time >=1.1
     , unix-compat >=0.2
   default-language: Haskell2010
-  if os(linux)
-    cpp-options: -DOS_Linux -DHAVE_NATIVE_WATCHER
-  if os(windows)
-    cpp-options: -DOS_Win32 -DHAVE_NATIVE_WATCHER
-  if os(darwin)
-    cpp-options: -DOS_Mac -DHAVE_NATIVE_WATCHER
-  if os(linux)
+  if os(linux) || os(windows) || os(darwin) || os(freebsd)
+    cpp-options: -DHAVE_NATIVE_WATCHER
+  if os(linux) || os(freebsd)
     other-modules:
         System.FSNotify.Linux
         System.FSNotify.Linux.Util
@@ -80,6 +76,9 @@
         System.FSNotify.OSX
     build-depends:
         hfsevents >=0.1.8
+  if os(freebsd)
+    build-depends:
+        hinotify >=0.4.1
 
 executable example
   main-is: Main.hs
@@ -105,12 +104,8 @@
     , unix-compat
     , unliftio
   default-language: Haskell2010
-  if os(linux)
-    cpp-options: -DOS_Linux -DHAVE_NATIVE_WATCHER
-  if os(windows)
-    cpp-options: -DOS_Win32 -DHAVE_NATIVE_WATCHER
-  if os(darwin)
-    cpp-options: -DOS_Mac -DHAVE_NATIVE_WATCHER
+  if os(linux) || os(windows) || os(darwin) || os(freebsd)
+    cpp-options: -DHAVE_NATIVE_WATCHER
   if !arch(wasm32)
     ghc-options: -threaded
 
@@ -142,12 +137,8 @@
     , unix-compat
     , unliftio >=0.2.20
   default-language: Haskell2010
-  if os(linux)
-    cpp-options: -DOS_Linux -DHAVE_NATIVE_WATCHER
-  if os(windows)
-    cpp-options: -DOS_Win32 -DHAVE_NATIVE_WATCHER
-  if os(darwin)
-    cpp-options: -DOS_Mac -DHAVE_NATIVE_WATCHER
+  if os(linux) || os(windows) || os(darwin) || os(freebsd)
+    cpp-options: -DHAVE_NATIVE_WATCHER
   if os(windows)
     build-depends:
         Win32
diff --git a/src/System/FSNotify.hs b/src/System/FSNotify.hs
--- a/src/System/FSNotify.hs
+++ b/src/System/FSNotify.hs
@@ -87,15 +87,15 @@
 import Data.Monoid
 #endif
 
-#ifdef OS_Linux
+#if defined(linux_HOST_OS) || defined(freebsd_HOST_OS)
 import System.FSNotify.Linux
 #endif
 
-#ifdef OS_Win32
+#ifdef mingw32_HOST_OS
 import System.FSNotify.Win32
 #endif
 
-#ifdef OS_Mac
+#ifdef darwin_HOST_OS
 import System.FSNotify.OSX
 #endif
 
@@ -156,7 +156,7 @@
 -- | Like 'startManager', but configurable.
 startManagerConf :: WatchConfig -> IO WatchManager
 startManagerConf conf = do
-# ifdef OS_Win32
+# ifdef mingw32_HOST_OS
   -- See https://github.com/haskell-fswatch/hfsnotify/issues/50
   unless rtsSupportsBoundThreads $ throwIO $ userError "startManagerConf must be called with -threaded on Windows"
 # endif
diff --git a/test/FSNotify/Test/EventTests.hs b/test/FSNotify/Test/EventTests.hs
--- a/test/FSNotify/Test/EventTests.hs
+++ b/test/FSNotify/Test/EventTests.hs
@@ -119,7 +119,7 @@
     (if isWin then withSingleWriteFile f "foo" else withOpenWritableAndWrite f "foo") $
       waitForEvents getEvents $ \events ->
         if | nested && not recursive -> events `shouldBe` []
-           | isMac -> case events of
+           | isMac || isFreeBSD -> case events of
                [Modified {..}] | poll && eventPath `equalFilePath` f && eventIsDirectory == IsFile -> return ()
                [ModifiedAttributes {..}] | not poll && eventPath `equalFilePath` f && eventIsDirectory == IsFile -> return ()
                _ -> expectationFailure $ "Got wrong events: " <> show events <> " (wanted file path " <> show f <> ")"
@@ -127,7 +127,7 @@
                [Modified {..}] | eventPath `equalFilePath` f && eventIsDirectory == IsFile -> return ()
                _ -> expectationFailure $ "Got wrong events: " <> show events <> " (wanted file path " <> show f <> ")"
 
-  when isLinux $ unless poll $ do
+  when (isLinux || isFreeBSD) $ unless poll $ do
     let setup f = liftIO $ do
           h <- openFile f WriteMode
           hPutStr h "asdf" >> hFlush h
diff --git a/test/FSNotify/Test/Util.hs b/test/FSNotify/Test/Util.hs
--- a/test/FSNotify/Test/Util.hs
+++ b/test/FSNotify/Test/Util.hs
@@ -78,6 +78,13 @@
 isLinux = False
 #endif
 
+isFreeBSD :: Bool
+#ifdef freebsd_HOST_OS
+isFreeBSD = True
+#else
+isFreeBSD = False
+#endif
+
 haveNativeWatcher :: Bool
 #ifdef HAVE_NATIVE_WATCHER
 haveNativeWatcher = True