diff --git a/hgis.cabal b/hgis.cabal
--- a/hgis.cabal
+++ b/hgis.cabal
@@ -1,5 +1,5 @@
 name: hgis
-version: 0.1.1.0
+version: 0.1.1.1
 cabal-version: >=1.10
 build-type: Simple
 license: BSD3
@@ -23,6 +23,11 @@
     type: git
     location: https://github.com/vmchale/hgis
 
+flag llvm-fast
+    description:
+        Enable build with llvm backend
+    default: False
+
 library
     exposed-modules:
         GIS.Exe.Opt
@@ -69,20 +74,24 @@
         Geometry.Shapefile.Internal
 
 executable hgis
+    
+    if flag(llvm-fast)
+        ghc-options: -threaded -rtsopts -with-rtsopts=-N -fllvm -optlo-O3 -O3
+    else
+        ghc-options: -threaded -rtsopts -with-rtsopts=-N
     main-is: MainPng.hs
     build-depends:
         base >=4.9.1.0 && <4.10,
-        hgis >=0.1.1.0 && <0.2
+        hgis >=0.1.1.1 && <0.2
     default-language: Haskell2010
     hs-source-dirs: app
-    ghc-options: -threaded -rtsopts -with-rtsopts=-N
 
 test-suite hgis-test
     type: exitcode-stdio-1.0
     main-is: Spec.hs
     build-depends:
         base >=4.9.1.0 && <4.10,
-        hgis >=0.1.1.0 && <0.2,
+        hgis >=0.1.1.1 && <0.2,
         hspec >=2.4.2 && <2.5
     default-language: Haskell2010
     hs-source-dirs: test