diff --git a/libavcodec/acelp_filters.c b/libavcodec/acelp_filters.c
index 03c4a544f6..a75d2291cd 100644
--- a/libavcodec/acelp_filters.c
+++ b/libavcodec/acelp_filters.c
@@ -85,22 +85,22 @@ void ff_acelp_convolve_circ(
         int16_t* fc_out,
         const int16_t* fc_in,
         const int16_t* filter,
-        int subframe_size)
+        int len)
 {
     int i, k;
 
-    memset(fc_out, 0, subframe_size * sizeof(int16_t));
+    memset(fc_out, 0, len * sizeof(int16_t));
 
     /* Since there are few pulses over an entire subframe (i.e. almost
        all fc_in[i] are zero) it is faster to loop over fc_in first. */
-    for(i=0; i<subframe_size; i++)
+    for(i=0; i<len; i++)
     {
         if(fc_in[i])
         {
             for(k=0; k<i; k++)
-                fc_out[k] += (fc_in[i] * filter[subframe_size + k - i]) >> 15;
+                fc_out[k] += (fc_in[i] * filter[len + k - i]) >> 15;
 
-            for(k=i; k<subframe_size; k++)
+            for(k=i; k<len; k++)
                 fc_out[k] += (fc_in[i] * filter[k - i]) >> 15;
         }
     }
diff --git a/libavcodec/acelp_filters.h b/libavcodec/acelp_filters.h
index 6436e10d18..324be3b63d 100644
--- a/libavcodec/acelp_filters.h
+++ b/libavcodec/acelp_filters.h
@@ -75,7 +75,7 @@ void ff_acelp_convolve_circ(
         int16_t* fc_out,
         const int16_t* fc_in,
         const int16_t* filter,
-        int subframe_size);
+        int len);
 
 /**
  * LP synthesis filter.