diff --git a/src/Synthesizer/LLVM/Generator/Private.hs b/src/Synthesizer/LLVM/Generator/Private.hs
--- a/src/Synthesizer/LLVM/Generator/Private.hs
+++ b/src/Synthesizer/LLVM/Generator/Private.hs
@@ -133,7 +133,6 @@
 
 instance (Tuple.Phi a, Tuple.Undefined a) => Monoid (T a) where
    mempty = empty
-   mappend = (<>)
 
 
 
diff --git a/synthesizer-llvm.cabal b/synthesizer-llvm.cabal
--- a/synthesizer-llvm.cabal
+++ b/synthesizer-llvm.cabal
@@ -1,6 +1,6 @@
 Cabal-Version:  2.2
 Name:           synthesizer-llvm
-Version:        1.2
+Version:        1.2.0.1
 License:        GPL-3.0-only
 License-File:   LICENSE
 Author:         Henning Thielemann <haskell@henning-thielemann.de>
@@ -59,7 +59,7 @@
   default:     False
 
 Source-Repository this
-  Tag:         1.2
+  Tag:         1.2.0.1
   Type:        darcs
   Location:    http://code.haskell.org/synthesizer/llvm/
 
@@ -95,7 +95,7 @@
 
   Build-Depends:
     -- base-4 needed for Control.Category
-    base >=4 && <5
+    base >=4.11 && <5
 
   Default-Language: Haskell98
   GHC-Options:    -Wall