diff --git a/pcg-random.cabal b/pcg-random.cabal
--- a/pcg-random.cabal
+++ b/pcg-random.cabal
@@ -1,5 +1,5 @@
 name:                pcg-random
-version:             0.1.3.7
+version:             0.1.4.0
 synopsis:            Haskell bindings to the PCG random number generator.
 description:
   PCG is a family of simple fast space-efficient statistically good
@@ -31,7 +31,7 @@
 custom-setup
  setup-depends:
    base >= 4 && <5,
-   Cabal,
+   Cabal < 4.0,
    cabal-doctest >= 1 && <1.1
 
 source-repository head
@@ -52,8 +52,8 @@
   other-extensions:    BangPatterns, CPP, ForeignFunctionInterface
   build-depends:
     base        >=4.3 && < 5,
-    primitive   >=0.4 && < 0.8,
-    random      >=1.0 && < 2.0,
+    primitive   >=0.7 && < 0.9,
+    random      >=1.2 && < 2.0,
     bytestring,
     entropy
   default-language:    Haskell2010
diff --git a/src/System/Random/PCG.hs b/src/System/Random/PCG.hs
--- a/src/System/Random/PCG.hs
+++ b/src/System/Random/PCG.hs
@@ -254,7 +254,7 @@
   {-# INLINE uniform1B #-}
 
 instance RandomGen FrozenGen where
-  next s = unsafeDupablePerformIO $ do
+  genWord64 s = unsafeDupablePerformIO $ do
     p <- malloc
     poke p s
     w1 <- pcg32_random_r p
@@ -262,7 +262,7 @@
     s' <- peek p
     free p
     return (wordsTo64Bit w1 w2, s')
-  {-# INLINE next #-}
+  {-# INLINE genWord64 #-}
 
   split s = unsafeDupablePerformIO $ do
     p <- malloc
diff --git a/src/System/Random/PCG/Class.hs b/src/System/Random/PCG/Class.hs
--- a/src/System/Random/PCG/Class.hs
+++ b/src/System/Random/PCG/Class.hs
@@ -50,6 +50,7 @@
 #include "MachDeps.h"
 #endif
 
+import qualified Data.Kind
 import Control.Monad
 import Data.Bits
 import Data.ByteString (useAsCString)
@@ -449,7 +450,7 @@
 -- Type family for fixed size integrals. For signed data types it's
 -- its unsigned couterpart with same size and for unsigned data types
 -- it's same type
-type family Unsigned a :: *
+type family Unsigned a :: Data.Kind.Type
 
 type instance Unsigned Int8  = Word8
 type instance Unsigned Int16 = Word16
diff --git a/src/System/Random/PCG/Fast.hs b/src/System/Random/PCG/Fast.hs
--- a/src/System/Random/PCG/Fast.hs
+++ b/src/System/Random/PCG/Fast.hs
@@ -223,15 +223,24 @@
   {-# INLINE uniform1B #-}
 
 instance RandomGen FrozenGen where
-  next s = unsafeDupablePerformIO $ do
+  genWord32 s = unsafeDupablePerformIO $ do
     p <- malloc
     poke p s
+    w <- pcg32f_random_r p
+    s' <- peek p
+    free p
+    return (w, s')
+  {-# INLINE genWord32 #-}
+
+  genWord64 s = unsafeDupablePerformIO $ do
+    p <- malloc
+    poke p s
     w1 <- pcg32f_random_r p
     w2 <- pcg32f_random_r p
     s' <- peek p
     free p
     return (wordsTo64Bit w1 w2, s')
-  {-# INLINE next #-}
+  {-# INLINE genWord64 #-}
 
   split s = unsafeDupablePerformIO $ do
     p  <- malloc
diff --git a/src/System/Random/PCG/Fast/Pure.hs b/src/System/Random/PCG/Fast/Pure.hs
--- a/src/System/Random/PCG/Fast/Pure.hs
+++ b/src/System/Random/PCG/Fast/Pure.hs
@@ -253,11 +253,16 @@
   {-# INLINE uniform1B #-}
 
 instance RandomGen FrozenGen where
-  next (F s) = (wordsTo64Bit w1 w2, F s'')
+  genWord32 (F s) = (w, F s')
     where
+      P s' w = pair s
+  {-# INLINE genWord32 #-}
+
+  genWord64 (F s) = (wordsTo64Bit w1 w2, F s'')
+    where
       P s'  w1 = pair s
       P s'' w2 = pair s'
-  {-# INLINE next #-}
+  {-# INLINE genWord64 #-}
 
   split (F s) = (mk w1 w2, mk w3 w4)
     where
diff --git a/src/System/Random/PCG/Pure.hs b/src/System/Random/PCG/Pure.hs
--- a/src/System/Random/PCG/Pure.hs
+++ b/src/System/Random/PCG/Pure.hs
@@ -303,11 +303,11 @@
   {-# INLINE uniform1B #-}
 
 instance RandomGen FrozenGen where
-  next (SetSeq s inc) = (wordsTo64Bit w1 w2, SetSeq s'' inc)
+  genWord64 (SetSeq s inc) = (wordsTo64Bit w1 w2, SetSeq s'' inc)
     where
       Pair s'  w1 = pair (SetSeq s inc)
       Pair s'' w2 = pair (SetSeq s' inc)
-  {-# INLINE next #-}
+  {-# INLINE genWord64 #-}
 
   split (SetSeq s inc) = (SetSeq s4 inc, mk w1 w2 w3 w4)
     where
diff --git a/src/System/Random/PCG/Single.hs b/src/System/Random/PCG/Single.hs
--- a/src/System/Random/PCG/Single.hs
+++ b/src/System/Random/PCG/Single.hs
@@ -221,7 +221,7 @@
 
 
 instance RandomGen FrozenGen where
-  next s = unsafeDupablePerformIO $ do
+  genWord64 s = unsafeDupablePerformIO $ do
     p <- malloc
     poke p s
     w1 <- pcg32s_random_r p
@@ -229,7 +229,7 @@
     s' <- peek p
     free p
     return (wordsTo64Bit w1 w2, s')
-  {-# INLINE next #-}
+  {-# INLINE genWord64 #-}
 
   split s = unsafeDupablePerformIO $ do
     p  <- malloc