diff --git a/posix-paths.cabal b/posix-paths.cabal
--- a/posix-paths.cabal
+++ b/posix-paths.cabal
@@ -1,5 +1,5 @@
 name:		posix-paths
-version:  0.2.0.4
+version:  0.2.0.5
 license:	BSD3
 license-file:	LICENSE
 maintainer:	jwlato@gmail.com
@@ -8,7 +8,7 @@
 category:       System
 description:
 	This package gives access to certain POSIX-based Filepath/Directory
-  services.  
+  services.
 	.
 	The package is not supported under Windows (except under Cygwin).
 extra-source-files: cbits/dirutils.h
@@ -25,7 +25,7 @@
     exposed-modules:    System.Posix.Directory.Foreign,
                         System.Posix.Directory.Traversals,
                         System.Posix.FilePath
-    build-depends:      base >= 4.2 && < 4.8,
+    build-depends:      base >= 4.2 && < 4.10,
                         bytestring >= 0.9.2.0 && < 0.12,
                         unix >= 2.5 && < 2.8
 
diff --git a/src/System/Posix/FilePath.hs b/src/System/Posix/FilePath.hs
--- a/src/System/Posix/FilePath.hs
+++ b/src/System/Posix/FilePath.hs
@@ -120,8 +120,8 @@
 -- prop> \path -> uncurry (BS.append) (splitExtension path) == path
 splitExtension :: RawFilePath -> (RawFilePath, ByteString)
 splitExtension x = if BS.null basename
-    then (x,"")
-    else (BS.concat [path,BS.init basename],BS.cons extSeparator fileExt)
+    then (x,BS.empty)
+    else (BS.append path (BS.init basename),BS.cons extSeparator fileExt)
   where
     (path,file) = splitFileNameRaw x
     (basename,fileExt) = BS.breakEnd isExtSeparator file
@@ -171,8 +171,8 @@
 addExtension :: RawFilePath -> ByteString -> RawFilePath
 addExtension file ext
     | BS.null ext = file
-    | isExtSeparator (BS.head ext) = BS.concat [file, ext]
-    | otherwise = BS.concat [file, BS.singleton extSeparator, ext]
+    | isExtSeparator (BS.head ext) = BS.append file ext
+    | otherwise = BS.intercalate (BS.singleton extSeparator) [file, ext]
 
 
 -- | Operator version of 'addExtension'
@@ -200,8 +200,8 @@
 -- prop> \path -> uncurry addExtension (splitExtensions path) == path
 splitExtensions :: RawFilePath -> (RawFilePath, ByteString)
 splitExtensions x = if BS.null basename
-    then (x,"")
-    else (BS.concat [path,basename],fileExt)
+    then (x,BS.empty)
+    else (BS.append path basename,fileExt)
   where
     (path,file) = splitFileNameRaw x
     (basename,fileExt) = BS.break isExtSeparator file
@@ -450,8 +450,8 @@
 combineRaw :: RawFilePath -> RawFilePath -> RawFilePath
 combineRaw a b | BS.null a = b
                   | BS.null b = a
-                  | isPathSeparator (BS.last a) = BS.concat [a, b]
-                  | otherwise = BS.concat [a,BS.singleton pathSeparator, b]
+                  | isPathSeparator (BS.last a) = BS.append a b
+                  | otherwise = BS.intercalate (BS.singleton pathSeparator) [a, b]
 
 -- | we don't even attempt to fully normalize file paths, this is just enough
 -- equality to test some operations.