diff --git a/packages/coding-agent/CHANGELOG.md b/packages/coding-agent/CHANGELOG.md
index 3136e113..4a9261c4 100644
--- a/packages/coding-agent/CHANGELOG.md
+++ b/packages/coding-agent/CHANGELOG.md
@@ -8,6 +8,7 @@
 
 ### Fixed
 
+- Fixed theme sharing across package scopes so extensions do not crash with `Theme not initialized` ([#4333](https://github.com/earendil-works/pi/issues/4333)).
 - Fixed keybinding hints to show Option instead of Alt on macOS ([#4289](https://github.com/earendil-works/pi/issues/4289)).
 - Fixed the interactive update notification to render the changelog as an OSC 8 hyperlink when the terminal supports hyperlinks ([#4280](https://github.com/earendil-works/pi/issues/4280)).
 
diff --git a/packages/coding-agent/src/modes/interactive/theme/theme.ts b/packages/coding-agent/src/modes/interactive/theme/theme.ts
index 955fa44a..30e4a233 100644
--- a/packages/coding-agent/src/modes/interactive/theme/theme.ts
+++ b/packages/coding-agent/src/modes/interactive/theme/theme.ts
@@ -658,6 +658,7 @@ function getDefaultTheme(): string {
 
 // Use globalThis to share theme across module loaders (tsx + jiti in dev mode)
 const THEME_KEY = Symbol.for("@earendil-works/pi-coding-agent:theme");
+const THEME_KEY_OLD = Symbol.for("@mariozechner/pi-coding-agent:theme");
 
 // Export theme as a getter that reads from globalThis
 // This ensures all module instances (tsx, jiti) see the same theme
@@ -671,6 +672,7 @@ export const theme: Theme = new Proxy({} as Theme, {
 
 function setGlobalTheme(t: Theme): void {
 	(globalThis as Record<symbol, Theme>)[THEME_KEY] = t;
+	(globalThis as Record<symbol, Theme>)[THEME_KEY_OLD] = t;
 }
 
 let currentThemeName: string | undefined;