diff --git a/src/services/ClipboardService.ts b/src/services/ClipboardService.ts
index 4ad2569a..a83cf4c0 100644
--- a/src/services/ClipboardService.ts
+++ b/src/services/ClipboardService.ts
@@ -28,7 +28,10 @@ export class ClipboardService {
     if ((document as any).selection) {
       (document as any).selection.empty();
     } else if (window.getSelection) {
-      window.getSelection().removeAllRanges();
+      let seln = window.getSelection();
+      if (seln) {
+        seln.removeAllRanges();
+      }
     }
   }
 
diff --git a/src/utils/highlight.ts b/src/utils/highlight.ts
index 07606d82..da5d69b6 100644
--- a/src/utils/highlight.ts
+++ b/src/utils/highlight.ts
@@ -73,5 +73,5 @@ export function highlight(source: string, lang: string = DEFAULT_LANG): string {
   if (!grammar) {
     grammar = Prism.languages[mapLang(lang)];
   }
-  return Prism.highlight(source, grammar);
+  return Prism.highlight(source, grammar, lang);
 }