diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,6 @@
+2021-07-07
+        * Version bump (3.4). (#231)
+
 2021-05-07
         * Version bump (3.3). (#217)
         * Remove unused type. (#110)
diff --git a/copilot-language.cabal b/copilot-language.cabal
--- a/copilot-language.cabal
+++ b/copilot-language.cabal
@@ -1,6 +1,6 @@
 cabal-version:       >=1.10
 name:                copilot-language
-version:             3.3
+version:             3.4
 synopsis:            A Haskell-embedded DSL for monitoring hard real-time
                      distributed systems.
 description:
@@ -40,8 +40,8 @@
                , mtl             >= 2.0 && < 3
                , ghc-prim        >= 0.3 && < 0.7
 
-               , copilot-core    >= 3.3 && < 3.4
-               , copilot-theorem >= 3.3 && < 3.4
+               , copilot-core    >= 3.4 && < 3.5
+               , copilot-theorem >= 3.4 && < 3.5
 
   exposed-modules: Copilot
                  , Copilot.Language