diff --git a/vlib/v/parser/struct.v b/vlib/v/parser/struct.v
index 687d470018..cddd38413c 100644
--- a/vlib/v/parser/struct.v
+++ b/vlib/v/parser/struct.v
@@ -390,9 +390,9 @@ fn (mut p Parser) interface_decl() ast.InterfaceDecl {
 	typ := table.new_type(reg_idx)
 	mut ts := p.table.get_type_symbol(typ)
 	// if methods were declared before, it's an error, ignore them
-	ts.methods.clear()
+	ts.methods = []table.Fn{cap:20}
 	// Parse methods
-	mut methods := []ast.FnDecl{}
+	mut methods := []ast.FnDecl{cap:20}
 	for p.tok.kind != .rcbr && p.tok.kind != .eof {
 		method_start_pos := p.tok.position()
 		line_nr := p.tok.line_nr
@@ -425,7 +425,8 @@ fn (mut p Parser) interface_decl() ast.InterfaceDecl {
 		if p.tok.kind.is_start_of_type() && p.tok.line_nr == line_nr {
 			method.return_type = p.parse_type()
 		}
-		method.comments = p.eat_comments()
+		mcomments := p.eat_comments()
+		method.comments = mcomments
 		methods << method
 		// println('register method $name')
 		return_type_sym := p.table.get_type_symbol(method.return_type)