diff --git a/gtk/OGApplication.m b/gtk/OGApplication.m
index 9456423..501d388 100644
--- a/gtk/OGApplication.m
+++ b/gtk/OGApplication.m
@@ -20,6 +20,8 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <gtk/gtk.h>
+
 #import "OGApplication.h"
 
 OF_APPLICATION_DELEGATE(OGApplication)