diff --git a/cblrepo.cabal b/cblrepo.cabal
--- a/cblrepo.cabal
+++ b/cblrepo.cabal
@@ -1,5 +1,5 @@
 name: cblrepo
-version: 0.6
+version: 0.6.1
 cabal-version: >= 1.6
 license: OtherLicense
 license-file: LICENSE-2.0
@@ -27,7 +27,7 @@
         OldPkgDB ConvertDB Remove
     build-depends: base ==4.5.*, cmdargs ==0.9.*, filepath ==1.3.*,
         directory ==1.1.*, Cabal ==1.14.*, json ==0.5.*,
-        bytestring ==0.9.*, tar ==0.4.*, zlib ==0.5.*, mtl ==2.0.*,
+        bytestring ==0.9.*, tar ==0.4.*, zlib ==0.5.*, mtl >=2.0 && <2.2,
         process ==1.1.*, Unixutils ==1.50.*, unix ==2.5.*,
         ansi-wl-pprint ==0.6.*