diff --git a/lang/bytecode.c b/lang/bytecode.c
index 33fc7c9..6c77a04 100644
--- a/lang/bytecode.c
+++ b/lang/bytecode.c
@@ -14,7 +14,7 @@
 	OP_END = 0x00,
 	OP_NUM = 0x01,
 	OP_RET = 0x03,
-	// 0x02 was an earlier variant of OP_DROP
+	OP_DROP_ONE = 0x02, // Unused old variant of OP_DROP
 	OP_CALL = 0x04,
 	OP_NONE = 0x05, // Formerly OP_NULL
 	OP_GET = 0x06,