diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,9 @@
+0.1.3.1 (2018-03-18)
+====================
+
+*   Put dependency on pcg-random behind a cabal flag, which is on by default.
+    This enables builds stackage nightly.
+
 0.1.3 (2018-03-17)
 ==================
 
diff --git a/benchmark/Implementations.hs b/benchmark/Implementations.hs
--- a/benchmark/Implementations.hs
+++ b/benchmark/Implementations.hs
@@ -1,13 +1,14 @@
-{-# LANGUAGE UnicodeSyntax #-}
-{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE MagicHash #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE UnboxedTuples #-}
-{-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE UnicodeSyntax #-}
 
 -- -------------------------------------------------------------------------- --
 -- |
 -- Module: Implementations
--- Copyright: (c) Lars Kuhtz <lakuhtz@gmail.com> 2017
+-- Copyright: (c) Lars Kuhtz <lakuhtz@gmail.com> 2017-2018
 -- License: MIT
 -- Maintainer: lakuhtz@gmail.com
 -- Stability: experimental
@@ -29,8 +30,10 @@
 , mwcMalloc32
 , mwcMalloc64
 
+#ifdef MIN_VERSION_pcg_random
 --
 , pcgMalloc64
+#endif
 ) where
 
 import Control.Exception (bracketOnError)
@@ -52,7 +55,9 @@
 import System.Entropy (getEntropy)
 import System.Random (randoms, getStdGen)
 import qualified System.Random.MWC as MWC (uniform, create, Gen)
+#ifdef MIN_VERSION_pcg_random
 import qualified System.Random.PCG as PCG (uniform, create, Gen)
+#endif
 
 import Benchmarks
 
@@ -70,7 +75,9 @@
     , Impl "mwc-malloc-8" mwcMalloc8
     , Impl "mwc-malloc-32" mwcMalloc32
     , Impl "mwc-malloc-64" mwcMalloc64
+#ifdef MIN_VERSION_pcg_random
     , Impl "pcg-malloc-64" pcgMalloc64
+#endif
     ]
 
 -- -------------------------------------------------------------------------- --
@@ -243,6 +250,7 @@
         let !(# !s', !b #) = internal (MWC.uniform gen ∷ IO Word8) s
         in Just (b, Box s')
 
+#ifdef MIN_VERSION_pcg_random
 -- -------------------------------------------------------------------------- --
 -- PCG Malloc64
 
@@ -281,4 +289,5 @@
                 poke curPtr b
                 loop8 $ curPtr `plusPtr` 1
             | otherwise = return ()
+#endif
 
diff --git a/benchmark/benchmark.hs b/benchmark/benchmark.hs
--- a/benchmark/benchmark.hs
+++ b/benchmark/benchmark.hs
@@ -1,9 +1,10 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE UnicodeSyntax #-}
 
 -- -------------------------------------------------------------------------- --
 -- |
 -- Module: Main
--- Copyright: (c) Lars Kuhtz <lakuhtz@gmail.com> 2017
+-- Copyright: (c) Lars Kuhtz <lakuhtz@gmail.com> 2017-2018
 -- License: MIT
 -- Maintainer: lakuhtz@gmail.com
 -- Stability: experimental
@@ -17,11 +18,15 @@
 import Benchmarks
 import Criterion.Main
 import qualified Data.ByteString.Random.MWC as MWC
+#ifdef MIN_VERSION_pcg_random
 import qualified Data.ByteString.Random.PCG as PCG
+#endif
 
 main ∷ IO ()
 main = defaultMain $ compareBenchmarks
     [ Impl "random-bytestring+mwc" MWC.random
+#ifdef MIN_VERSION_pcg_random
     , Impl "random-bytestring+pcg" PCG.random
+#endif
     ]
 
diff --git a/random-bytestring.cabal b/random-bytestring.cabal
--- a/random-bytestring.cabal
+++ b/random-bytestring.cabal
@@ -1,5 +1,5 @@
 Name: random-bytestring
-Version: 0.1.3
+Version: 0.1.3.1
 Synopsis: Efficient generation of random bytestrings
 Description:
     Efficient generation of random bytestrings. The implementation
@@ -18,9 +18,9 @@
     applications. They are /not/ suitable for cryptographic
     applications.
     .
-    ![benchmarks](https://hackage.haskell.org/package/random-bytestring-0.1.3/src/benchmarks.png)
+    ![benchmarks](https://hackage.haskell.org/package/random-bytestring-0.1.3.1/src/benchmarks.png)
     .
-    ![detailed benchmarks](https://hackage.haskell.org/package/random-bytestring-0.1.3/src/benchmarks-details.png)
+    ![detailed benchmarks](https://hackage.haskell.org/package/random-bytestring-0.1.3.1/src/benchmarks-details.png)
 
 Homepage: https://www.github.com/larskuhtz/random-bytestring
 License: MIT
@@ -43,6 +43,10 @@
     type: git
     location: https://www.github.com/larskuhtz/random-bytestring
 
+flag with-pcg
+  Description: compile with support for PCG from pcg-random
+  default: True
+
 Library
     default-language: Haskell2010
     hs-source-dirs: src
@@ -50,19 +54,23 @@
     exposed-modules:
         Data.ByteString.Random
         Data.ByteString.Random.Internal
-        Data.ByteString.Random.PCG
         Data.ByteString.Random.MWC
 
     build-depends:
         base >= 4.7 && < 4.12,
         bytestring >= 0.10,
-        mwc-random >= 0.13,
-        pcg-random >= 0.1
+        mwc-random >= 0.13
 
     if impl(ghc < 7.10)
         build-depends:
             nats >= 1.1
 
+    if flag(with-pcg)
+        exposed-modules:
+            Data.ByteString.Random.PCG
+        build-depends:
+            pcg-random >= 0.1
+
     ghc-options: -Wall -O2
 
 Benchmark benchmark
@@ -80,7 +88,6 @@
         entropy >= 0.3,
         ghc-prim >= 0.3,
         mwc-random >= 0.13,
-        pcg-random >= 0.1,
         primitive >= 0.6,
         random >= 1.1,
         cryptonite >= 0.24
@@ -92,6 +99,10 @@
     if impl(ghc < 7.10)
         buildable: False
 
+    if flag(with-pcg)
+        build-depends:
+            pcg-random >= 0.1
+
     other-modules:
         Benchmarks
         Implementations
@@ -111,7 +122,6 @@
         entropy >= 0.3,
         ghc-prim >= 0.3,
         mwc-random >= 0.13,
-        pcg-random >= 0.1,
         primitive >= 0.6,
         random >= 1.1,
         cryptonite >= 0.24
@@ -123,6 +133,10 @@
     if impl(ghc < 7.10)
         buildable: False
 
+    if flag(with-pcg)
+        build-depends:
+            pcg-random >= 0.1
+
     other-modules:
         Benchmarks,
         Implementations
@@ -142,7 +156,6 @@
         entropy >= 0.3,
         ghc-prim >= 0.3,
         mwc-random >= 0.13,
-        pcg-random >= 0.1,
         primitive >= 0.6,
         random >= 1.1,
         cryptonite >= 0.24
@@ -153,6 +166,10 @@
 
     if impl(ghc < 7.10)
         buildable: False
+
+    if flag(with-pcg)
+        build-depends:
+            pcg-random >= 0.1
 
     other-modules:
         Benchmarks,