diff --git a/.changeset/fix-shiki-theme-priority.md b/.changeset/fix-shiki-theme-priority.md
new file mode 100644
index 00000000..9a4e6c2a
--- /dev/null
+++ b/.changeset/fix-shiki-theme-priority.md
@@ -0,0 +1,11 @@
+---
+"streamdown": patch
+---
+
+Fix: `shikiTheme` prop priority chain is now fully reachable.
+
+Previously, `shikiTheme` had a default value in the props destructuring (`= defaultShikiTheme`), making the `plugins?.code?.getThemes()` fallback unreachable in both orderings. The fix removes the destructuring default and moves it to the end of the nullish coalescing chain, so all three levels are reachable:
+
+1. Explicit `shikiTheme` prop (highest priority)
+2. Code plugin's `getThemes()` (second priority)
+3. Built-in `defaultShikiTheme` (final fallback)
diff --git a/packages/streamdown/index.tsx b/packages/streamdown/index.tsx
index be32d9fd..5e666cff 100644
--- a/packages/streamdown/index.tsx
+++ b/packages/streamdown/index.tsx
@@ -438,7 +438,7 @@ export const Streamdown = memo(
     rehypePlugins = defaultRehypePluginsArray,
     remarkPlugins = defaultRemarkPluginsArray,
     className,
-    shikiTheme = defaultShikiTheme,
+    shikiTheme,
     mermaid,
     controls = true,
     isAnimating = false,
@@ -609,7 +609,8 @@ export const Streamdown = memo(
     // Combined context value - single object reduces React tree overhead
     const contextValue = useMemo<StreamdownContextType>(
       () => ({
-        shikiTheme: plugins?.code?.getThemes() ?? shikiTheme,
+        shikiTheme:
+          shikiTheme ?? plugins?.code?.getThemes() ?? defaultShikiTheme,
         controls,
         isAnimating,
         lineNumbers,