diff --git a/libcelt/kfft_single.h b/libcelt/kfft_single.h
index de647e77ff3532d16b59055ac31fd3b3cf199dec..e97e44616cc21b2d58d0748f183ce9d512b43bd2 100644
--- a/libcelt/kfft_single.h
+++ b/libcelt/kfft_single.h
@@ -38,7 +38,7 @@
 
 #define real16_fft_alloc(length) NULL
 #define real16_fft_free(state)
-#define BITREV(state, i) i
+#define BITREV(state, i) (i)
 
 #define real16_fft_inplace(state, X, nx)\
     (\