diff --git a/stepmania/src/arch/LowLevelWindow/LowLevelWindow_X11.cpp b/stepmania/src/arch/LowLevelWindow/LowLevelWindow_X11.cpp
index bf11c329ac..31f7318989 100644
--- a/stepmania/src/arch/LowLevelWindow/LowLevelWindow_X11.cpp
+++ b/stepmania/src/arch/LowLevelWindow/LowLevelWindow_X11.cpp
@@ -4,6 +4,7 @@
 #include "RageException.h"
 #include "archutils/Unix/X11Helper.h"
 #include "PrefsManager.h" // XXX
+#include "RageDisplay.h" // VideoModeParams
 
 #include <stack>
 #include <math.h>	// ceil()
diff --git a/stepmania/src/arch/LowLevelWindow/LowLevelWindow_X11.h b/stepmania/src/arch/LowLevelWindow/LowLevelWindow_X11.h
index 9f8eb7b7c6..ede083ff95 100644
--- a/stepmania/src/arch/LowLevelWindow/LowLevelWindow_X11.h
+++ b/stepmania/src/arch/LowLevelWindow/LowLevelWindow_X11.h
@@ -3,6 +3,7 @@
 #ifndef LOW_LEVEL_WINDOW_X11_H
 #define LOW_LEVEL_WINDOW_X11_H
 
+#include "RageDisplay.h" // VideoModeParams
 #include "LowLevelWindow.h"
 
 class LowLevelWindow_X11 : public LowLevelWindow
@@ -12,7 +13,7 @@ public:
 	~LowLevelWindow_X11();
 
 	void *GetProcAddress(CString s);
-	CString TryVideoMode(VideoModeParams p, bool &bNewDeviceOut);
+	CString TryVideoMode(const VideoModeParams &p, bool &bNewDeviceOut);
 	bool IsSoftwareRenderer( CString &sError );
 	void SwapBuffers();