diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Changelog for the [`clash-ghc`](http://hackage.haskell.org/package/clash-ghc) package
 
+## 0.6.21 *July 19th 2016*
+* Fixes bugs:
+  * Rounding error in `logBase` calculation
+  * VHDL: Incorrect primitive for `Index`s `*#`
+  * VHDL: Incorrect handling of `Index`s `fromInteger#` and `maxBound#` primitives for values larger than 2^MACHINE_WIDTH
+
 ## 0.6.20 *July 15th 2016*
 * New features:
   * Better error location reporting
diff --git a/clash-ghc.cabal b/clash-ghc.cabal
--- a/clash-ghc.cabal
+++ b/clash-ghc.cabal
@@ -1,5 +1,5 @@
 Name:                 clash-ghc
-Version:              0.6.20
+Version:              0.6.21
 Synopsis:             CAES Language for Synchronous Hardware
 Description:
   CλaSH (pronounced ‘clash’) is a functional hardware description language that
@@ -78,7 +78,7 @@
 
   Build-Depends:      array                     >= 0.4      && < 0.6,
                       base                      >= 4.3.1.0  && < 5,
-                      bifunctors                >= 4.1.1    && < 5.4,
+                      bifunctors                >= 4.1.1    && < 5.5,
                       bytestring                >= 0.9      && < 0.11,
                       containers                >= 0.5.4.0  && < 0.6,
                       directory                 >= 1.2      && < 1.3,
@@ -94,13 +94,13 @@
                       unbound-generics          >= 0.1      && < 0.4,
                       unordered-containers      >= 0.2.1.0  && < 0.3,
 
-                      clash-lib                 >= 0.6.18   && < 0.7,
+                      clash-lib                 >= 0.6.19   && < 0.7,
                       clash-systemverilog       >= 0.6.7    && < 0.7,
-                      clash-vhdl                >= 0.6.14   && < 0.7,
+                      clash-vhdl                >= 0.6.15   && < 0.7,
                       clash-verilog             >= 0.6.7    && < 0.7,
                       clash-prelude             >= 0.10.10  && < 0.11,
-                      ghc-typelits-extra        >= 0.1.2    && < 0.2,
-                      ghc-typelits-natnormalise >= 0.4.2    && < 0.5,
+                      ghc-typelits-extra        >= 0.1.3    && < 0.2,
+                      ghc-typelits-natnormalise >= 0.4.3    && < 0.5,
                       deepseq                   >= 1.3.0.2  && < 1.5,
                       time                      >= 1.4.0.1  && < 1.7
 
diff --git a/src-ghc/CLaSH/GHC/LoadModules.hs b/src-ghc/CLaSH/GHC/LoadModules.hs
--- a/src-ghc/CLaSH/GHC/LoadModules.hs
+++ b/src-ghc/CLaSH/GHC/LoadModules.hs
@@ -119,8 +119,9 @@
                                 , DynFlags.Opt_MonomorphismRestriction
                                 ]
                   let ghcTyLitNormPlugin = GHC.mkModuleName "GHC.TypeLits.Normalise"
+                      ghcTyLitExtrPlugin = GHC.mkModuleName "GHC.TypeLits.Extra.Solver"
                   let dfPlug = dfDis { DynFlags.pluginModNames = nub $
-                                          ghcTyLitNormPlugin : DynFlags.pluginModNames dfDis
+                                          ghcTyLitNormPlugin : ghcTyLitExtrPlugin : DynFlags.pluginModNames dfDis
                                      }
                   return dfPlug