diff --git a/src/cmt_cat.c b/src/cmt_cat.c
index af95dcb..a9ba723 100644
--- a/src/cmt_cat.c
+++ b/src/cmt_cat.c
@@ -346,20 +346,16 @@ int cmt_cat_untyped(struct cmt *cmt, struct cmt_untyped *untyped,
 int cmt_cat_histogram(struct cmt *cmt, struct cmt_histogram *histogram,
                       struct cmt_map *filtered_map)
 {
-    int i;
-    double val;
     int ret;
     char **labels = NULL;
     struct cmt_map *map;
     struct cmt_opts *opts;
     struct cmt_histogram *hist;
-    uint64_t timestamp;
     struct cmt_histogram_buckets *buckets;
     int64_t buckets_count;
 
     map = histogram->map;
     opts = map->opts;
-    timestamp = cmt_metric_get_timestamp(&map->metric);
 
     ret = cmt_cat_copy_label_keys(map, (char **) &labels);
     if (ret == -1) {