diff --git a/RSA.cabal b/RSA.cabal
--- a/RSA.cabal
+++ b/RSA.cabal
@@ -1,6 +1,6 @@
 name:       RSA
 category:   Cryptography, Codec
-version:    2.3.0
+version:    2.3.1
 license:    BSD3
 license-file: LICENSE
 author:     Adam Wick <awick@galois.com>
@@ -35,6 +35,7 @@
   type:           exitcode-stdio-1.0
   Main-Is:        Test.hs
   hs-source-dirs: src,.
+  other-modules:  Codec.Crypto.RSA.Pure
   build-depends:  base                       >= 4.6     && < 7.0,
                   binary                     >  0.7     && < 1.0,
                   bytestring                 >  0.8     && < 0.12,
diff --git a/Test.hs b/Test.hs
--- a/Test.hs
+++ b/Test.hs
@@ -96,10 +96,13 @@
 
 instance Arbitrary LargePrime where
   arbitrary =
-    do Right (g :: HashDRBG) <- (newGen . BSS.pack) `fmap` replicateM 4096 arbitrary
-       case largeRandomPrime g 64 of
-         Left _ -> fail "Large prime generation failure."
-         Right (i, _) -> return (LP i)
+    do seed <- BSS.pack `fmap` replicateM 4096 arbitrary
+       case newGen seed of
+        Left _ -> fail "DRBG initialization error."
+        Right (g :: HashDRBG) ->
+          case largeRandomPrime g 64 of
+            Left _ -> fail "Large prime generation failure."
+            Right (i, _) -> return (LP i)
 
 data KeyPairIdx = KPI Int
  deriving (Show)