cleaner pointer alignment logic for autoconf-based builds
diff --git a/configure.in b/configure.in
index 119762d..661e960 100644
--- a/configure.in
+++ b/configure.in
@@ -41,6 +41,8 @@
 AC_SYS_LARGEFILE
 AC_FUNC_FSEEKO
 
+AC_CHECK_SIZEOF(void*,0)
+
 #@@@ new name is AC_CONFIG_HEADERS
 AM_CONFIG_HEADER(config.h)