diff --git a/libs/nativewindow/include/apex/window.h b/libs/nativewindow/include/apex/window.h
index 2d1354c..0923438 100644
--- a/libs/nativewindow/include/apex/window.h
+++ b/libs/nativewindow/include/apex/window.h
@@ -39,6 +39,19 @@
     // clang-format on
 };
 
+/*
+ * Internal extension of compatibility value for ANativeWindow_setFrameRate. */
+enum ANativeWindow_FrameRateCompatibilityInternal {
+    /**
+     * This surface belongs to an app on the High Refresh Rate Deny list, and needs the display
+     * to operate at the exact frame rate.
+     *
+     * This is used internally by the platform and should not be used by apps.
+     * @hide
+     */
+    ANATIVEWINDOW_FRAME_RATE_EXACT = 100,
+};
+
 /**
  * Prototype of the function that an ANativeWindow implementation would call
  * when ANativeWindow_cancelBuffer is called.