diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,7 @@
+0.1.2.1:
+  * Relax Cabal constraint.
+  * Remove halberd constraint. It made the last version unbuildable.
+
 0.1.2:
   * Actual order independent choosing.
   * Added test cases.
diff --git a/halberd.cabal b/halberd.cabal
--- a/halberd.cabal
+++ b/halberd.cabal
@@ -1,5 +1,5 @@
 name:                halberd
-version:             0.1.2
+version:             0.1.2.1
 license:             BSD3
 license-file:        LICENSE
 author:              Erik Hesselink, Simon Meier, Tom Lokhorst, Roman Cheplyaka
@@ -25,7 +25,7 @@
                      , haskell-packages == 0.2.*
                      , haskell-names    == 0.2.*
                      , haskell-src-exts == 1.14.*
-                     , Cabal            >= 1.17   &&  < 1.19
+                     , Cabal            >= 1.16   &&  < 1.19
                      , mtl              >= 2.0    &&  < 2.2
                      , safe             == 0.3.*
                      , syb              >= 0.3    &&  < 0.5
@@ -41,8 +41,8 @@
 
 executable halberd
   build-depends:       base             >= 4.5    &&  < 4.7
-                     , Cabal            >= 1.17   &&  < 1.19
-                     , halberd          == 0.1.1
+                     , Cabal            >= 1.16   &&  < 1.19
+                     , halberd
                      , haskell-names    == 0.2.*
                      , haskell-packages == 0.2.*
                      , haskell-src-exts == 1.14.*
@@ -56,9 +56,9 @@
 
 Test-suite halberd-tests
   build-depends:       base                 >= 4.5    && < 4.7
-                     , Cabal                >= 1.17   && < 1.19
+                     , Cabal                >= 1.16   && < 1.19
                      , containers           >= 0.4    && < 0.6
-                     , halberd              == 0.1.1
+                     , halberd
                      , HUnit                == 1.2.*
                      , test-framework       == 0.8.*
                      , test-framework-hunit == 0.3.*