diff -ur qhull-2009.1-orig/src/Makefile.am qhull-2009.1/src/Makefile.am
--- qhull-2009.1-orig/src/Makefile.am	2013-06-25 20:40:09 -0400
+++ qhull-2009.1/src/Makefile.am	2013-06-25 20:44:01 -0400
@@ -23,6 +23,7 @@
   mem.c
 
 # how:
+libqhull_la_CPPFLAGS = -DBUILDING_QHULL
 libqhull_la_LDFLAGS = -no-undefined -version-info 5:0:0 -lm
 
 ### Utility programs
diff -ur qhull-2009.1-orig/src/qhull.h qhull-2009.1/src/qhull.h
--- qhull-2009.1-orig/src/qhull.h	2004-01-30 17:38:32 -0500
+++ qhull-2009.1/src/qhull.h	2013-06-25 20:42:03 -0400
@@ -51,9 +51,19 @@
 
 #include "user.h"      /* user defineable constants */
 
+#ifdef _MSC_VER
+# ifdef BUILDING_QHULL
+#  define QHULL_EXTERN extern __declspec(dllexport)
+# else
+#  define QHULL_EXTERN extern __declspec(dllimport)
+# endif
+#else
+# define QHULL_EXTERN extern
+#endif
+
 /*============ constants and basic types ====================*/
 
-extern char *qh_version; /* defined in global.c */
+QHULL_EXTERN char *qh_version; /* defined in global.c */
 
 /*-<a                             href="qh-geom.htm#TOC"
   >--------------------------------</a><a name="coordT">-</a>
@@ -376,10 +386,10 @@
 typedef struct qhT qhT;
 #if qh_QHpointer
 #define qh qh_qh->
-extern qhT *qh_qh;     /* allocated in global.c */
+QHULL_EXTERN qhT *qh_qh;     /* allocated in global.c */
 #else
 #define qh qh_qh.
-extern qhT qh_qh;
+QHULL_EXTERN qhT qh_qh;
 #endif
 
 struct qhT {