diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,7 @@
+2025-09-07
+        * Version bump (4.5.1). (#666)
+        * Relax version constraint on `ogma-extra`. (#645)
+
 2025-07-07
         * Version bump (4.5). (#642)
         * Include in mainline. (#624)
diff --git a/copilot-visualizer.cabal b/copilot-visualizer.cabal
--- a/copilot-visualizer.cabal
+++ b/copilot-visualizer.cabal
@@ -1,6 +1,6 @@
 cabal-version:       >= 1.10
 name:                copilot-visualizer
-version:             4.5
+version:             4.5.1
 synopsis:            Visualizer for Copilot.
 description:
   Visualizer for Copilot.
@@ -61,14 +61,14 @@
     filepath   >= 1.4.2   && < 1.6,
     hint       >= 0.9.0   && < 1.10,
     pretty     >= 1.0     && < 1.2,
-    ogma-extra >= 1.6.0   && < 1.7,
+    ogma-extra >= 1.6.0   && < 1.10,
     text       >= 1.2.3.1 && < 2.2,
     websockets >= 0.12.7  && < 0.14,
 
-    copilot             >= 4.5 && < 4.6,
-    copilot-core        >= 4.5 && < 4.6,
-    copilot-interpreter >= 4.5 && < 4.6,
-    copilot-language    >= 4.5 && < 4.6
+    copilot             >= 4.5.1 && < 4.6,
+    copilot-core        >= 4.5.1 && < 4.6,
+    copilot-interpreter >= 4.5.1 && < 4.6,
+    copilot-language    >= 4.5.1 && < 4.6
 
   exposed-modules:
 
@@ -121,7 +121,7 @@
   build-depends:
     base               >= 4.9 && < 5,
 
-    copilot            >= 4.5 && < 4.6,
+    copilot            >= 4.5.1 && < 4.6,
     copilot-visualizer
 
   if flag(examples)