diff --git a/parsing/parser.mly b/parsing/parser.mly
index 6210cc5..709895d 100644
--- a/parsing/parser.mly
+++ b/parsing/parser.mly
@@ -1356,6 +1356,8 @@ expr:
       { unclosed "object" 1 "end" 4 }
   | expr attribute
       { Exp.attr $1 $2 }
+  | LPAREN COLON core_type RPAREN expr %prec below_SHARP
+      { mkexp (Pexp_constraint ($5, $3)) }
 ;
 simple_expr:
     val_longident