diff --git a/modules/lwjgl/lwjglx/src/main/java/org/lwjgl/input/Keyboard.java b/modules/lwjgl/lwjglx/src/main/java/org/lwjgl/input/Keyboard.java
index d1ff345b96..1fa1a92af2 100644
--- a/modules/lwjgl/lwjglx/src/main/java/org/lwjgl/input/Keyboard.java
+++ b/modules/lwjgl/lwjglx/src/main/java/org/lwjgl/input/Keyboard.java
@@ -395,7 +395,7 @@ private static void read() {
     public static boolean isKeyDown(int key) {
         if (!created)
             throw new IllegalStateException("Keyboard must be created before you can query key state");
-        if(key >= KEYBOARD_SIZE) return false;
+        if(key < 0 || key >= keyDownBuffer.limit()) return false;
         return keyDownBuffer.get(key) != 0;
     }