diff --git a/src/vim9.h b/src/vim9.h
index 3b14ffc..1b5a58b 100644
--- a/src/vim9.h
+++ b/src/vim9.h
@@ -500,7 +500,7 @@
 
 // Number of entries used by stack frame for a function call.
 // - ec_dfunc_idx:   function index
-// - ec_iidx:        instruction index
+// - ec_iidx:	     instruction index
 // - ec_instr:       instruction list pointer
 // - ec_outer:	     stack used for closures
 // - funclocal:	     function-local data