diff --git a/src/output/plugins/SndioOutputPlugin.hxx b/src/output/plugins/SndioOutputPlugin.hxx
index 98d815594..a4698637e 100644
--- a/src/output/plugins/SndioOutputPlugin.hxx
+++ b/src/output/plugins/SndioOutputPlugin.hxx
@@ -17,11 +17,11 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#include "../OutputAPI.hxx"
-
 #ifndef MPD_SNDIO_OUTPUT_PLUGIN_HXX
 #define MPD_SNDIO_OUTPUT_PLUGIN_HXX
 
+#include "../OutputAPI.hxx"
+
 class Mixer;
 class MixerListener;