diff --git a/hoauth2.cabal b/hoauth2.cabal
--- a/hoauth2.cabal
+++ b/hoauth2.cabal
@@ -2,7 +2,7 @@
 name:               hoauth2
 
 -- http://wiki.haskell.org/Package_versioning_policy
-version:            2.13.0
+version:            2.13.1
 synopsis:           Haskell OAuth2 authentication client
 description:
   This is Haskell binding of OAuth2 Authorization framework and Bearer Token Usage framework.
@@ -70,7 +70,7 @@
     , binary                >=0.8    && <0.11
     , bytestring            >=0.9    && <0.13
     , containers            >=0.6    && <0.8
-    , crypton               ^>=0.32
+    , crypton               >=0.32   && <0.35
     , data-default          ^>=0.7
     , exceptions            >=0.8.3  && <0.11
     , http-conduit          >=2.1    && <2.4