diff --git a/Control/DeepSeq.hs b/Control/DeepSeq.hs
--- a/Control/DeepSeq.hs
+++ b/Control/DeepSeq.hs
@@ -179,6 +179,18 @@
   grnf args = grnf args . unM1
   {-# INLINEABLE grnf #-}
 
+#if MIN_VERSION_base(4,9,0)
+  -- | Because 'URec' did not exist prior to @base-4.9@, this instance is only
+  -- defined on @base-4.9@ or later.
+  --
+  -- @since 1.4.5.0
+instance GNFData arity (URec a) where
+  grnf _ = rwhnf -- Every URec data instance consists of a single data
+                 -- constructor containing a single strict field, so reducing
+                 -- any URec instance to WHNF suffices to reduce it to NF.
+  {-# INLINEABLE grnf #-}
+#endif
+
 instance (GNFData arity a, GNFData arity b) => GNFData arity (a :*: b) where
   grnf args (x :*: y) = grnf args x `seq` grnf args y
   {-# INLINEABLE grnf #-}
diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,10 @@
 # Changelog for [`deepseq` package](http://hackage.haskell.org/package/deepseq)
 
+## 1.4.5.0
+
+  * Add `GNFData` for URec
+    This will enable deriving NFData instances for unboxed types
+
 ## 1.4.4.0 *Sep 2018*
 
   * Bundled with GHC 8.6.1
diff --git a/deepseq.cabal b/deepseq.cabal
--- a/deepseq.cabal
+++ b/deepseq.cabal
@@ -1,6 +1,6 @@
 cabal-version:  1.12
 name:           deepseq
-version:        1.4.4.0
+version:        1.4.5.0
 -- NOTE: Don't forget to update ./changelog.md
 
 license:        BSD3
@@ -25,8 +25,8 @@
     details.
 
 build-type:     Simple
-tested-with:    GHC==8.6.1,
-                GHC==8.4.3, GHC==8.4.2, GHC==8.4.1,
+tested-with:    GHC==8.6.5, GHC==8.6.4,GHC==8.6.3,GHC==8.6.3,GHC==8.6.1,
+                GHC==8.4.4, GHC==8.4.3, GHC==8.4.2, GHC==8.4.1,
                 GHC==8.2.2, GHC==8.2.1,
                 GHC==8.0.2, GHC==8.0.1,
                 GHC==7.10.3, GHC==7.10.2, GHC==7.10.1,
@@ -63,7 +63,7 @@
   if impl(ghc>=7.8)
     other-extensions: EmptyCase
 
-  build-depends: base       >= 4.5 && < 4.13,
+  build-depends: base       >= 4.5 && < 4.16,
                  array      >= 0.4 && < 0.6
   ghc-options: -Wall