diff --git a/src/vim.h b/src/vim.h
index 1fd24ad..16949ae 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -2019,11 +2019,11 @@
 #define VV_ARGV		93
 #define VV_LEN		94	// number of v: vars
 
-// used for v_number in VAR_SPECIAL
-#define VVAL_FALSE	0L
-#define VVAL_TRUE	1L
-#define VVAL_NONE	2L
-#define VVAL_NULL	3L
+// used for v_number in VAR_BOOL and VAR_SPECIAL
+#define VVAL_FALSE	0L	// VAR_BOOL
+#define VVAL_TRUE	1L	// VAR_BOOL
+#define VVAL_NONE	2L	// VAR_SPECIAL
+#define VVAL_NULL	3L	// VAR_SPECIAL
 
 // Type values for type().
 #define VAR_TYPE_NUMBER	    0