diff --git a/include/qpdf/DLL.hh b/include/qpdf/DLL.hh
new file mode 100644
index 0000000..0b72ff0
--- /dev/null
+++ b/include/qpdf/DLL.hh
@@ -0,0 +1,10 @@
+#ifndef __QPDF_DLL_HH__
+#define __QPDF_DLL_HH__
+
+#ifdef _WIN32
+# define DLL_EXPORT __declspec(dllexport)
+#else
+# define DLL_EXPORT
+#endif
+
+#endif // __QPDF_DLL_HH__