diff --git a/libjrpc/src/targets/typescript.rs b/libjrpc/src/targets/typescript.rs
index 205ea48..0e49213 100644
--- a/libjrpc/src/targets/typescript.rs
+++ b/libjrpc/src/targets/typescript.rs
@@ -476,9 +476,12 @@ impl<F: Flavour> Compile for TypeScriptCompiler<F> {
         for field in definition.fields.iter() {
             let typ = Self::type_to_typescript_ext(&field.typ);
 
+            let opt = if field.typ.is_optional() { "?" } else { "" };
+
             f.a1(format!(
-                "public {}: {};",
+                "public {}{}: {};",
                 Self::fix_keyword_name(&field.name),
+                opt,
                 typ
             ));
         }