diff --git a/ir.py b/ir.py
index 1bada00..b025842 100644
--- a/ir.py
+++ b/ir.py
@@ -222,7 +222,7 @@ class Application:
 			return unwrap_opt(self.first.try_apply(self.arg)).codegen()
 		else:
 			match self.first:
-				case Application(Builtin(Builtin.BB_PLUS), addend1):
+				case Application(Builtin(Builtin.BB_PLUS()), addend1):
 					return f'({addend1.codegen()} + {self.arg.codegen()})'
 				case Builtin(Builtin.BB_PLUS_CONST(n)):
 					return f'({self.arg.codegen()}{n:+})'