diff --git a/libasn1compiler/asn1c_misc.c b/libasn1compiler/asn1c_misc.c
index c8cd2e7..7483a20 100644
--- a/libasn1compiler/asn1c_misc.c
+++ b/libasn1compiler/asn1c_misc.c
@@ -261,8 +261,8 @@
  * standard will give it an unsigned type.
  * It is defined here as a constant expression.
  */
-#define	LEFTMIN		2147483647
-#define	RIGHTMAX	(-LEFTMIN-1)
+#define	RIGHTMAX	2147483647	/* of 32-bit integer type */
+#define	LEFTMIN		(-RIGHTMAX-1)	/* of 32-bit integer type */
 
 	/* Descend to the terminal type */
 	expr = asn1f_find_terminal_type_ex(arg->asn, expr);