diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,6 @@
+2025-09-07
+        * Version bump (4.5.1). (#666)
+
 2025-07-07
         * Version bump (4.5). (#642)
         * Include `copilot-bluespec` in mainline `copilot` repo. (#623)
diff --git a/copilot-bluespec.cabal b/copilot-bluespec.cabal
--- a/copilot-bluespec.cabal
+++ b/copilot-bluespec.cabal
@@ -1,6 +1,6 @@
 cabal-version             : >= 1.10
 name                      : copilot-bluespec
-version                   : 4.5
+version                   : 4.5.1
 synopsis                  : A compiler for Copilot targeting FPGAs.
 description               :
   This package is a back-end from Copilot to FPGAs in Bluespec.
@@ -44,7 +44,7 @@
                           , filepath          >= 1.4    && < 1.6
                           , pretty            >= 1.1.2  && < 1.2
 
-                          , copilot-core      >= 4.5    && < 4.6
+                          , copilot-core      >= 4.5.1  && < 4.6
                           , language-bluespec >= 0.1    && < 0.2
 
   exposed-modules         : Copilot.Compile.Bluespec