--- include/plConfig.h.in.orig	2015-04-12 10:08:04 UTC
+++ include/plConfig.h.in
@@ -43,7 +43,8 @@
 #ifndef __PLCONFIG_H__
 #define __PLCONFIG_H__
 
-#ifdef PLPLOT_HAVE_CONFIG_H
+// plplot_config.h won't be installed: don't let it be used by consumers
+#if defined(PLPLOT_HAVE_CONFIG_H) && defined(_IS_BUILDING_PLPLOT_PORT_)
 #  include <plplot_config.h>
 #endif