diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,8 @@
+2025-01-07
+        * Version bump (4.2). (#577)
+        * Remove uses of Copilot.Core.Expr.UExpr.uExprType,uExprExpr. (#565)
+        * Bump upper constraint on containers, data-default. (#570)
+
 2024-11-07
         * Version bump (4.1). (#561)
         * Standardize changelog format. (#550)
diff --git a/copilot-theorem.cabal b/copilot-theorem.cabal
--- a/copilot-theorem.cabal
+++ b/copilot-theorem.cabal
@@ -14,7 +14,7 @@
   <https://copilot-language.github.io>.
 
 
-version                   : 4.1
+version                   : 4.2
 license                   : BSD3
 license-file              : LICENSE
 maintainer                : Ivan Perez <ivan.perezdominguez@nasa.gov>
@@ -48,8 +48,8 @@
   build-depends           : base                  >= 4.9 && < 5
                           , bimap                 (>= 0.3 && < 0.4) || (>= 0.5 && < 0.6)
                           , bv-sized              >= 1.0.2 && < 1.1
-                          , containers            >= 0.4 && < 0.7
-                          , data-default          >= 0.7 && < 0.8
+                          , containers            >= 0.4 && < 0.8
+                          , data-default          >= 0.7 && < 0.9
                           , directory             >= 1.3 && < 1.4
                           , libBF                 >= 0.6.2 && < 0.7
                           , mtl                   >= 2.0 && < 2.4
@@ -63,8 +63,8 @@
                           , xml                   >= 1.3 && < 1.4
                           , what4                 >= 1.3 && < 1.7
 
-                          , copilot-core          >= 4.1 && < 4.2
-                          , copilot-prettyprinter >= 4.1 && < 4.2
+                          , copilot-core          >= 4.2 && < 4.3
+                          , copilot-prettyprinter >= 4.2 && < 4.3
 
   exposed-modules         : Copilot.Theorem
                           , Copilot.Theorem.Prove
diff --git a/src/Copilot/Theorem/What4.hs b/src/Copilot/Theorem/What4.hs
--- a/src/Copilot/Theorem/What4.hs
+++ b/src/Copilot/Theorem/What4.hs
@@ -324,7 +324,7 @@
          args' <- mapM computeArg args
          return (nm, guard', args')
   where
-   computeArg (CE.UExpr { CE.uExprType = tp, CE.uExprExpr = ex }) = do
+   computeArg (CE.UExpr tp ex) = do
      v <- translateExpr sym mempty ex (RelativeOffset 0)
      return (Some tp, v)