diff --git a/lib/rouge/lexers/typescript.rb b/lib/rouge/lexers/typescript.rb
index 353ca7ffd5..52f95e7695 100644
--- a/lib/rouge/lexers/typescript.rb
+++ b/lib/rouge/lexers/typescript.rb
@@ -18,6 +18,13 @@ class Typescript < Javascript
       filenames '*.ts', '*.d.ts'
 
       mimetypes 'text/typescript'
+
+      prepend :statement do
+        rule %r/(#{Javascript.id_regex})(\??)(\s*)(:)/ do
+          groups Name::Label, Punctuation, Text, Punctuation
+          push :expr_start
+        end
+      end
     end
   end
 end
diff --git a/spec/visual/samples/typescript b/spec/visual/samples/typescript
index 6d9511dc1d..7379879409 100644
--- a/spec/visual/samples/typescript
+++ b/spec/visual/samples/typescript
@@ -167,7 +167,7 @@ declare module "foo" {
     export interface IFoo {
         theObject: any;
         aWord: string;
-        aNumber: number;
+        aNumber?: number;
     }
 }