diff --git a/include/gsm/api.h b/include/gsm/api.h
new file mode 100644
index 0000000..03c4842
--- /dev/null
+++ b/include/gsm/api.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2011 Free Software Foundation, Inc.
+ *
+ * This file is part of GNU Radio
+ *
+ * GNU Radio is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3, or (at your option)
+ * any later version.
+ *
+ * GNU Radio is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef INCLUDED_GSM_API_H
+#define INCLUDED_GSM_API_H
+
+#include <gnuradio/attributes.h>
+
+#ifdef gnuradio_gsm_EXPORTS
+#  define GSM_API __GR_ATTR_EXPORT
+#else
+#  define GSM_API __GR_ATTR_IMPORT
+#endif
+
+#endif /* INCLUDED_GSM_API_H */