diff --git a/include/opus_custom.h b/include/opus_custom.h
index 22ca318ab80a2999c808a9b58edf03039686310b..d4d33976f56b344ba1455346baea50bb8ea760d3 100644
--- a/include/opus_custom.h
+++ b/include/opus_custom.h
@@ -227,7 +227,7 @@ OPUS_CUSTOM_EXPORT OPUS_WARN_UNUSED_RESULT int opus_custom_encode(
   * by a convenience macro.
   * @see opus_encoderctls
   */
-OPUS_CUSTOM_EXPORT int opus_custom_encoder_ctl(OpusCustomEncoder * restrict st, int request, ...) OPUS_ARG_NONNULL(1);
+OPUS_CUSTOM_EXPORT int opus_custom_encoder_ctl(OpusCustomEncoder * OPUS_RESTRICT st, int request, ...) OPUS_ARG_NONNULL(1);
 
 /* Decoder */