1 files changed, 3 insertions, 2 deletions
diff --git a/include/mruby/irep.h b/include/mruby/irep.h
index 856b12099..498b58ca3 100644
--- a/include/mruby/irep.h
+++ b/include/mruby/irep.h
@@ -11,10 +11,11 @@
 extern "C" {
 #endif
 
+/* Program data array struct */
 typedef struct mrb_irep {
   uint32_t idx;
-  uint16_t nlocals;
-  uint16_t nregs;
+  uint16_t nlocals;        /* Number of local variables */
+  uint16_t nregs;          /* Number of register variables */
   uint8_t flags;
 
   mrb_code *iseq;