diff --git a/src/Data/CSS/Preprocessor/PsuedoClasses.hs b/src/Data/CSS/Preprocessor/PsuedoClasses.hs
--- a/src/Data/CSS/Preprocessor/PsuedoClasses.hs
+++ b/src/Data/CSS/Preprocessor/PsuedoClasses.hs
@@ -8,7 +8,7 @@
 import Data.CSS.Syntax.Selector
 import Data.CSS.Syntax.Tokens
 
-import Data.Text as Txt
+import Data.Text as Txt hiding (elem)
 import Data.Maybe (fromMaybe, listToMaybe)
 import Data.HashMap.Lazy as HM
 import Data.Function ((&))
diff --git a/stylist.cabal b/stylist.cabal
--- a/stylist.cabal
+++ b/stylist.cabal
@@ -10,7 +10,7 @@
 -- PVP summary:      +-+------- breaking API changes
 --                   | | +----- non-breaking API additions
 --                   | | | +--- code changes with no API change
-version:             2.4.0.0
+version:             2.4.0.1
 
 -- A short (one-line) description of the package.
 synopsis:            Apply CSS styles to a document tree.
@@ -68,7 +68,7 @@
   -- other-extensions:    
   
   -- Other library packages from which modules are imported.
-  build-depends:       base >=4.9 && <=4.12, css-syntax >=0.1 && <0.2, text,
+  build-depends:       base >=4.9 && <5, css-syntax >=0.1 && <0.2, text,
                         unordered-containers >= 0.2 && <0.3, hashable,
                         network-uri >= 2.6 && <2.7, async >= 2.1 && <2.3,
                         regex-tdfa >= 1.3
@@ -87,8 +87,9 @@
   type:     exitcode-stdio-1.0
   main-is:              Test.hs
   other-modules:        Data.CSS.Syntax.StyleSheet, Data.CSS.Syntax.Selector, Data.CSS.Style
-  build-depends:       base >=4.9 && <=4.12, css-syntax >=0.1 && <0.2, text,
+  build-depends:       base >=4.9 && <5, css-syntax >=0.1 && <0.2, text,
                         unordered-containers >= 0.2 && <0.3, hashable,
-                        network-uri >= 2.6 && <2.7, async >= 2.1 && <2.3, hspec, QuickCheck,
+                        network-uri >= 2.6 && <2.7, async >= 2.1 && <2.3,
+                        regex-tdfa >= 1.3, hspec, QuickCheck,
                         scientific >= 0.3 && <1.0, regex-tdfa >= 1.3
   ghc-options: -Wall