--- tags.h.~1.103.~	2003-06-12 10:58:55.000000000 +1000
+++ tags.h	2003-06-21 11:19:56.000000000 +1000
@@ -49,7 +49,9 @@
 #define SCM_T_SIGNED_BITS_MIN LONG_MIN
 #endif
 
-#if SCM_SIZEOF_UINTPTR_T != 0 && defined(UINTPTR_MAX)
+/* On solaris 7 and 8, Sun workshop cc has UINTPTR_MAX defined to empty.  To
+   avoid uintptr_t in this case we require UINTPTR_MAX-0 != 0.  */
+#if SCM_SIZEOF_UINTPTR_T != 0 && defined(UINTPTR_MAX) && UINTPTR_MAX-0 != 0
 typedef uintptr_t scm_t_bits;
 #define SIZEOF_SCM_T_BITS SCM_SIZEOF_UINTPTR_T
 #define SCM_T_BITS_MAX UINTPTR_MAX