diff --git a/README.md b/README.md
index 58cda20..246c4e4 100644
--- a/README.md
+++ b/README.md
@@ -434,7 +434,7 @@ stmt       = expr_stmt | assignment | connect | print | return | block ;
 expr_stmt  = expr ( ';' )? ;
 assignment = ID '=' ( expr | ref ) ';' ;
 connect    = ID '->' ID ';' ;
-print      = 'print' ( expr ) ';' ;
+print      = 'print' expr? ';' ;
 return     = 'return' expr? ';' ;
 block      = '{' decl* '}' ;