diff --git a/.changeset/old-chicken-turn.md b/.changeset/old-chicken-turn.md
new file mode 100644
index 0000000..624ec6f
--- /dev/null
+++ b/.changeset/old-chicken-turn.md
@@ -0,0 +1,5 @@
+---
+"prism-react-renderer": patch
+---
+
+Fixed bug where an undefined theme would cause a runtime error.
diff --git a/packages/prism-react-renderer/src/index.ts b/packages/prism-react-renderer/src/index.ts
index 16f4486..b1ef889 100644
--- a/packages/prism-react-renderer/src/index.ts
+++ b/packages/prism-react-renderer/src/index.ts
@@ -10,8 +10,10 @@ import { HighlightProps, PrismLib } from "./types"
  */
 const Highlight = (props: HighlightProps) =>
   createElement(InternalHighlight, {
-    prism: Prism as PrismLib,
-    theme: themes.vsDark,
     ...props,
+    prism: props.prism || (Prism as PrismLib),
+    theme: props.theme || themes.vsDark,
+    code: props.code,
+    language: props.language,
   })
 export { Highlight, Prism, themes }