Add DL_IMPORT(returntype) for all officially exported functions.
diff --git a/Include/cStringIO.h b/Include/cStringIO.h
index c1328de..53673ba 100644
--- a/Include/cStringIO.h
+++ b/Include/cStringIO.h
@@ -106,7 +106,7 @@
 #define PycStringIO_OutputCheck(O) \
   ((O)->ob_type==PycStringIO->OutputType)
 
-static void *
+static DL_IMPORT(void *)
 xxxPyCObject_Import(module_name, name)
   char *module_name;
   char *name;