diff --git a/src/java/org/lwjgl/opengl/Display.java b/src/java/org/lwjgl/opengl/Display.java
index 8cee12d0..83c4fbbe 100644
--- a/src/java/org/lwjgl/opengl/Display.java
+++ b/src/java/org/lwjgl/opengl/Display.java
@@ -153,6 +153,8 @@ public final class Display {
 	 * @throws LWJGLException if the display mode could not be set
 	 */
 	public static void setDisplayMode(DisplayMode mode) throws LWJGLException {
+		if (mode == null)
+			throw new NullPointerException("mode must be non-null");
 		current_mode = mode;
 		if (isCreated()) {
 			destroyWindow();