diff --git a/include/opus_custom.h b/include/opus_custom.h
index 22ca318a..d4d33976 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 */