diff --git a/libavcodec/aacdec_template.c b/libavcodec/aacdec_template.c
index 2a2d43f0a4..4cbbc6023a 100644
--- a/libavcodec/aacdec_template.c
+++ b/libavcodec/aacdec_template.c
@@ -1211,7 +1211,7 @@ static av_cold int aac_decode_init(AVCodecContext *avctx)
     AAC_RENAME_32(ff_mdct_init)(&ac->mdct_small,  8, 1, 1.0 / RANGE15(128.0));
     AAC_RENAME_32(ff_mdct_init)(&ac->mdct_ltp,   11, 0, RANGE15(-2.0));
 #if !USE_FIXED
-    ret = ff_mdct15_init(&ac->mdct480, 1, 5, -1.0f/(16*1024*960));
+    ret = ff_mdct15_init(&ac->mdct480, 1, 5, 1.0f/(16*1024*960));
     if (ret < 0)
         return ret;
 #endif