diff --git a/src/Xml2X.hs b/src/Xml2X.hs
--- a/src/Xml2X.hs
+++ b/src/Xml2X.hs
@@ -149,7 +149,8 @@
 
 -- | Render KEGG inforation from a set of UniProtAcc's.
 showKegg :: KoAnnotations -> [BlastFlat] -> String
-showKegg ks fs = unwords $ map show $ concatMap (flip M.lookup ks) $ map chop $ map subject fs
+showKegg ks fs = unwords $ map show $ concatMap mlookup $ map chop $ map subject fs
+    where mlookup = maybe [] return . flip M.lookup ks
 
 -- | Render GO information from a set of UniProtAcc's.
 showGo :: GoDefinitions -> GoAnnotations -> [BlastFlat] -> String
diff --git a/xml2x.cabal b/xml2x.cabal
--- a/xml2x.cabal
+++ b/xml2x.cabal
@@ -1,5 +1,5 @@
 Name:           xml2x
-Version:        0.4.1
+Version:        0.4.2
 License:        GPL
 License-File:   LICENSE
 
@@ -16,7 +16,7 @@
 Build-Type:     Simple
 Tested-With:    GHC==6.8.2
 
-Build-Depends:  base>3, bio >= 0.3.4, containers, bytestring, array, xhtml, directory
+Build-Depends:  base>3 && <4.2, bio >= 0.3.4, containers, bytestring, array, xhtml, directory
 -- Build-Depends: base, bio      - GHC 6.6
 -- Build-Depends: base, bio, fps - GHC 6.4