diff --git a/src/vim.h b/src/vim.h
index 784fa3a..05af5a1 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -1801,6 +1801,7 @@
     CT_DEBUG	    // use df_instr_debug, overrules CT_PROFILE
 } compiletype_T;
 
+// Keep in sync with INSTRUCTIONS().
 #ifdef FEAT_PROFILE
 # define COMPILE_TYPE(ufunc) (debug_break_level > 0 ? CT_DEBUG : do_profiling == PROF_YES && (ufunc)->uf_profiling ? CT_PROFILE : CT_NONE)
 #else