diff -Nur jpeg-7.orig/jmorecfg.h jpeg-7/jmorecfg.h
--- jpeg-7.orig/jmorecfg.h	2009-08-21 00:26:13.000000000 -0400
+++ jpeg-7/jmorecfg.h	2009-08-21 00:54:17.000000000 -0400
@@ -189,11 +189,30 @@
 #define METHODDEF(type)		static type
 /* a function used only in its module: */
 #define LOCAL(type)		static type
-/* a function referenced thru EXTERNs: */
-#define GLOBAL(type)		type
+
+// GLOBAL(type)
 /* a reference to a GLOBAL function: */
-#define EXTERN(type)		extern type
 
+// EXTERN(type)
+/* a function referenced thru EXTERNs: */
+
+#if defined _WIN32 || defined __CYGWIN__
+   #ifdef JPEG_DLL // Must be defined if building or using jpeg as a DLL
+      #ifdef jpeg_EXPORTS
+         #define GLOBAL(type)         __declspec(dllexport) type
+         #define EXTERN(type)  extern __declspec(dllexport) type
+      #else
+         #define GLOBAL(type)         __declspec(dllimport) type
+         #define EXTERN(type)  extern __declspec(dllimport) type
+      #endif
+   #else
+      #define GLOBAL(type)          type
+      #define EXTERN(type)   extern type
+   #endif
+#else
+   #define GLOBAL(type)		type
+   #define EXTERN(type)		extern type
+#endif
 
 /* This macro is used to declare a "method", that is, a function pointer.
  * We want to supply prototype parameters if the compiler can cope.