diff --git a/libavcodec/wma.c b/libavcodec/wma.c
index 6c7e14b250..2bbb0994cc 100644
--- a/libavcodec/wma.c
+++ b/libavcodec/wma.c
@@ -302,8 +302,8 @@ int ff_wma_init(AVCodecContext * avctx, int flags2)
     for(i = 0; i < s->nb_block_sizes; i++) {
         int n;
         n = 1 << (s->frame_len_bits - i);
-        ff_sine_window_init(ff_sine_windows[i], n);
-        s->windows[i] = ff_sine_windows[i];
+        ff_sine_window_init(ff_sine_windows[s->frame_len_bits - i - 7], n);
+        s->windows[i] = ff_sine_windows[s->frame_len_bits - i - 7];
     }
 
     s->reset_block_lengths = 1;