diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,12 @@
 # ChangeLog
 
+## 0.2.4.1
+
+* Fixes generated Storable instances to have a `sizeOf` definition
+  which works with `-XStrict`. See [#13][]
+
+[#13]: https://github.com/fpco/th-utilities/issues/1
+
 ## 0.2.4.0
 
 * Compatibility with GHC-8.10
diff --git a/src/TH/Derive/Storable.hs b/src/TH/Derive/Storable.hs
--- a/src/TH/Derive/Storable.hs
+++ b/src/TH/Derive/Storable.hs
@@ -54,7 +54,7 @@
     pokeMethod <- pokeExpr
     let methods =
             [ FunD (mkName "alignment") [Clause [WildP] (NormalB alignmentMethod) []]
-            , FunD (mkName "sizeOf") [Clause [WildP] (NormalB sizeOfMethod) []]
+            , FunD (mkName "sizeOf") [Clause [] (NormalB sizeOfMethod) []]
             , FunD (mkName "peek") [Clause [VarP ptrName] (NormalB peekMethod) []]
             , FunD (mkName "poke") [Clause [VarP ptrName, VarP valName] (NormalB pokeMethod) []]
             ]
@@ -81,7 +81,7 @@
     -- [[Int]] expression, where the inner lists are the sizes of the
     -- fields. Each member of the outer list corresponds to a different
     -- constructor.
-    sizeExpr = appE (varE 'maximum) $
+    sizeExpr = appE (varE 'const) $ appE (varE 'maximum) $
         listE [ appE (varE 'sum) (listE [sizeOfExpr ty | (_, ty) <- fields])
               | (DataCon _ _ _ fields) <- cons
               ]
diff --git a/th-utilities.cabal b/th-utilities.cabal
--- a/th-utilities.cabal
+++ b/th-utilities.cabal
@@ -1,13 +1,13 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.31.1.
+-- This file has been generated from package.yaml by hpack version 0.33.0.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 50c08bc61c9ae9c17ffbb564778e8b933569d268767798c7a9c1a14ee7bed17d
+-- hash: 4ead6810c97333043130d21e0a0d11b6c9254be283938497d1ebb222e7552598
 
 name:           th-utilities
-version:        0.2.4.0
+version:        0.2.4.1
 synopsis:       Collection of useful functions for use with Template Haskell
 category:       Template Haskell
 homepage:       https://github.com/fpco/th-utilities#readme