diff --git a/code/filter.c b/code/filter.c
index 15c46fd..fba03f9 100644
--- a/code/filter.c
+++ b/code/filter.c
@@ -69,15 +69,10 @@ mp_obj_t filter_convolve(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_a
             int top_n = MIN(len_c, len_a - k);
             int bot_n = MAX(-k, 0);
             for(int n=bot_n; n<top_n; n++) {
-            mp_float_t* a_ptr = a_items + bot_n + k;
-            mp_float_t* a_end = a_ptr + (top_n - bot_n);
-            mp_float_t* c_ptr = c_items + len_c - bot_n - 1;
-            for(; a_ptr != a_end;) {
                 int idx_c = len_c - n - 1;
                 int idx_a = n+k;
                 mp_float_t ai = ndarray_get_float_value(a->array->items, a->array->typecode, idx_a);
                 mp_float_t ci = ndarray_get_float_value(c->array->items, c->array->typecode, idx_c);
-                }
                 accum += ai * ci;
             }
             *outptr++ = accum;