diff --git a/tyvm.c b/tyvm.c
index b4a8dee..06f053f 100644
--- a/tyvm.c
+++ b/tyvm.c
@@ -46,6 +46,7 @@ enum registers {
     RG_COUNT
 };
 
+/* Trap codes used for OP_TRAP */
 enum trapcodes {
     TRAP_GETC  = 0x20,  // get charcter from keyboard
     TRAP_OUT   = 0x21,  // output a character