diff --git a/parser/src/grammar.pest b/parser/src/grammar.pest
index 16903b5..0800ebf 100644
--- a/parser/src/grammar.pest
+++ b/parser/src/grammar.pest
@@ -233,7 +233,7 @@ self_param = {
 }
 
 method = {
-    export? ~ type_expr ~ identifier ~ generics? ~ "(" ~ self_param? ~ param_list? ~ ")" ~ block
+    export? ~ type_expr ~ identifier ~ generics? ~ "(" ~ self_param? ~ ("," ~ param_list?)? ~ ")" ~ block
 }
 
 class_decl = {