diff --git a/lib_dec/dec_tcx.c b/lib_dec/dec_tcx.c
index 1f7aae46999e6253bf119e523ae7cdede127e529..f4684f7a6966a3d53cbbaac33bb3bc843af56e86 100644
--- a/lib_dec/dec_tcx.c
+++ b/lib_dec/dec_tcx.c
@@ -359,7 +359,7 @@ void IMDCT_flt(
 #ifdef IVAS_FLOAT_FIXED
                     Word32 x_fx[L_MDCT_OVLP_MAX + L_FRAME_PLUS + L_MDCT_OVLP_MAX];
                     Word16 win_fx[810] = { 0 };
-                    Word16 q_x = Q16, q_win, x_e_hdrm;
+                    Word16 q_x = Q15, q_win, x_e_hdrm;
                     x_e_hdrm = sub(q_x, 15);
                     q_win = q_x + x_e_hdrm - 16;
                     for ( int k = 0; k < L_ola + L_win; k++ )