diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -7,7 +7,7 @@
 Usage
 -----
 
-Cgrep 6.6.3. Usage: cgrep [OPTION] [PATTERN] files...
+Cgrep 6.6.4. Usage: cgrep [OPTION] [PATTERN] files...
 
 cgrep [OPTIONS] [ITEM]
 
diff --git a/cgrep.cabal b/cgrep.cabal
--- a/cgrep.cabal
+++ b/cgrep.cabal
@@ -1,6 +1,6 @@
 Name:                cgrep
 Description:         Cgrep: a context-aware grep for source codes
-Version:             6.6.3
+Version:             6.6.4
 Synopsis:            Command line tool
 Homepage:            http://awgn.github.io/cgrep/
 License:             GPL-2
diff --git a/src/Main.hs b/src/Main.hs
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -45,7 +45,7 @@
 import System.Directory
 import System.FilePath ((</>), takeFileName)
 import System.Environment
-import System.PosixCompat.Files
+import System.PosixCompat.Files as PosixCompat
 import System.IO
 import System.Exit
 import System.Process (readProcess)
@@ -102,7 +102,7 @@
                forM_ dirs $ \path -> do
                     let dirname = takeFileName path
                     lstatus <- getSymbolicLinkStatus path
-                    when ( deference_recursive opts || not (isSymbolicLink lstatus)) $
+                    when ( deference_recursive opts || not (PosixCompat.isSymbolicLink lstatus)) $
                         unless (dirname `elem` prunedir) $ do -- this is a good directory (unless already visited)!
                             cpath <- canonicalizePath path
                             unless (cpath `Set.member` visited) $ withRecursiveContents opts path langs prunedir (Set.insert cpath visited) action