diff --git a/include/osmocore/rate_ctr.h b/include/osmocore/rate_ctr.h
index 47fd5a3..85fe5c1 100644
--- a/include/osmocore/rate_ctr.h
+++ b/include/osmocore/rate_ctr.h
@@ -49,9 +49,8 @@
 	struct llist_head list;
 	/* Pointer to the counter group class */
 	const struct rate_ctr_group_desc *desc;
+	/* The index of this ctr_group within its class */
 	unsigned int idx;
-	/* The name prefix generated from desc->group_prefix_fmt and index */
-	char *name_prefix;
 	/* Actual counter structures below */
 	struct rate_ctr ctr[0];
 };
diff --git a/src/rate_ctr.c b/src/rate_ctr.c
index bde090a..e48c779 100644
--- a/src/rate_ctr.c
+++ b/src/rate_ctr.c
@@ -52,9 +52,6 @@
 
 	group->desc = desc;
 	group->idx = idx;
-	/* Generate the Group prefix from the user-specified index */
-	group->name_prefix = talloc_size(group, strlen(desc->group_prefix_fmt) + 20);
-	sprintf(group->name_prefix, desc->group_prefix_fmt, idx);
 
 	llist_add(&group->list, &rate_ctr_groups);