diff --git a/libavcodec/acelp_filters.c b/libavcodec/acelp_filters.c
index 6cd23ea174..b5a6660066 100644
--- a/libavcodec/acelp_filters.c
+++ b/libavcodec/acelp_filters.c
@@ -24,8 +24,6 @@
 
 #include "avcodec.h"
 #include "acelp_filters.h"
-#define FRAC_BITS 13
-#include "mathops.h"
 
 const int16_t ff_acelp_interp_filter[61] =
 { /* (0.15) */
@@ -152,8 +150,8 @@ void ff_acelp_high_pass_filter(
 
     for(i=0; i<length; i++)
     {
-        tmp =  MULL(hpf_f[0], 15836);                     /* (14.13) = (13.13) * (1.13) */
-        tmp += MULL(hpf_f[1], -7667);                     /* (13.13) = (13.13) * (0.13) */
+        tmp =  (hpf_f[0]* 15836LL)>>13;                   /* (14.13) = (13.13) * (1.13) */
+        tmp += (hpf_f[1]* -7667LL)>>13;                   /* (13.13) = (13.13) * (0.13) */
         tmp += 7699 * (in[i] - 2*in[i-1] + in[i-2]); /* (14.13) =  (0.13) * (14.0) */
 
         out[i] = av_clip_int16((tmp + 0x800) >> 12);      /* (15.0) = 2 * (13.13) = (14.13) */