I'm trying to update FreshLib http://homepages.inf.ed.ac.uk/jcheney/programs/freshlib/ to work with the current GHC version. Now it works fine in GHCi, but trying to compile with ghc --make gives this result: [1 of 5] Compiling NominalBase ( NominalBase.hs, NominalBase.o ) Loading package ghc-prim ... linking ... done. Loading package integer ... linking ... done. Loading package base ... linking ... done. Loading package syb ... linking ... done. Loading package base-3.0.3.0 ... linking ... done. Loading package array-0.2.0.0 ... linking ... done. Loading package packedstring-0.1.0.1 ... linking ... done. Loading package containers-0.2.0.0 ... linking ... done. Loading package pretty-1.0.1.0 ... linking ... done. Loading package template-haskell ... linking ... done. Loading package bytestring-0.9.1.4 ... linking ... done. Loading package syb-with-class-0.4 ... linking ... done. C:\Users\Alexey\AppData\Local\Temp\/ghc1892_0/ghc1892_0.s: Assembler messages: C:\Users\Alexey\AppData\Local\Temp\/ghc1892_0/ghc1892_0.s:557: Error: symbol `_N ominalBase_zdgtoName_closure' is already defined C:\Users\Alexey\AppData\Local\Temp\/ghc1892_0/ghc1892_0.s:585: Error: symbol `_N ominalBase_zdgtoName_info' is already defined C:\Users\Alexey\AppData\Local\Temp\/ghc1892_0/ghc1892_0.s:637: Error: symbol `_N ominalBase_zdgfromName_closure' is already defined C:\Users\Alexey\AppData\Local\Temp\/ghc1892_0/ghc1892_0.s:665: Error: symbol `_N ominalBase_zdgfromName_info' is already defined Yours, Alexey Romanov