diff --git a/src/gdal.h b/src/gdal.h
index be81f552e..aaefa6f82 100644
--- a/src/gdal.h
+++ b/src/gdal.h
@@ -1,3 +1,6 @@
+#include <Rcpp.h>
+class OGRSpatialReference;
+
 void set_error_handler(void);
 void unset_error_handler(void);
 OGRSpatialReference *handle_axis_order(OGRSpatialReference *sr);