diff --git a/src/support/UntypedLexer.mll b/src/support/UntypedLexer.mll
index e9d9377..a1d24d0 100644
--- a/src/support/UntypedLexer.mll
+++ b/src/support/UntypedLexer.mll
@@ -34,6 +34,8 @@ rule read = parse
   | "->"         { ARROW }
   | '('		 { LPAR }
   | ')'		 { RPAR }
+  | '{'		 { LBRACE }
+  | '}'		 { RBRACE }
   | '*'		 { STAR }
   | ','		 { COMMA }
   | '='		 { EQ }
diff --git a/src/support/UntypedParser.mly b/src/support/UntypedParser.mly
index 3ad71d0..617a4bf 100644
--- a/src/support/UntypedParser.mly
+++ b/src/support/UntypedParser.mly
@@ -13,6 +13,8 @@
 %token ARROW "->"
 %token LPAR "("
 %token RPAR ")"
+%token LBRACE "{"
+%token RBRACE "}"
 %token STAR "*"
 %token COMMA ","
 %token EQ "="
@@ -96,7 +98,7 @@ let typ_arrow :=
 let typ_atom :=
   | x = tyvar ;
     { STLC.Constr (Structure.Var x) }
-  | "(" ; tys = separated_list ("*", typ) ; ")" ;
+  | "{" ; tys = separated_list ("*", typ) ; "}" ;
     { STLC.Constr (Structure.Prod tys) }
   | "(" ; ~ = typ ; ")" ; <>