diff --git a/lib/activate/dev_manager.c b/lib/activate/dev_manager.c
index 513aaa82b..0036bac89 100644
--- a/lib/activate/dev_manager.c
+++ b/lib/activate/dev_manager.c
@@ -59,7 +59,7 @@ struct lv_layer {
 	const char *old_name;
 };
 
-static const char thin_layer[] = "tpool";
+static const char _thin_layer[] = "tpool";
 
 int read_only_lv(struct logical_volume *lv, struct lv_activate_opts *laopts)
 {
@@ -879,13 +879,12 @@ int dev_manager_thin_pool_percent(struct dev_manager *dm,
 	char *name;
 	const char *dlid;
 
-	/*
-	 * Build a name for the top layer.
-	 */
-	if (!(name = dm_build_dm_name(dm->mem, lv->vg->name, lv->name, thin_layer)))
+	/* Build a name for the top layer */
+	if (!(name = dm_build_dm_name(dm->mem, lv->vg->name, lv->name,
+				      _thin_layer)))
 		return_0;
 
-	if (!(dlid = build_dm_uuid(dm->mem, lv->lvid.s, thin_layer)))
+	if (!(dlid = build_dm_uuid(dm->mem, lv->lvid.s, _thin_layer)))
 		return_0;
 
 	log_debug("Getting device status percentage for %s", name);
@@ -1166,7 +1165,7 @@ static int _add_lv_to_dtree(struct dev_manager *dm, struct dm_tree *dtree,
 		/* FIXME code from _create_partial_dtree() should be moved here */
 		if (!_add_lv_to_dtree(dm, dtree, seg_lv(seg, 0), origin_only))
 			return_0;
-		if (!_add_dev_to_dtree(dm, dtree, lv, thin_layer))
+		if (!_add_dev_to_dtree(dm, dtree, lv, _thin_layer))
 			return_0;
 	} else if (lv_is_thin_volume(lv) &&
 		   !_add_lv_to_dtree(dm, dtree, seg->pool_lv, origin_only))
@@ -1559,11 +1558,11 @@ static int _add_segment_to_dtree(struct dev_manager *dm,
 	} else if (lv_is_cow(seg->lv) && !layer) {
 		if (!_add_new_lv_to_dtree(dm, dtree, seg->lv, laopts, "cow"))
 			return_0;
-	} else if ((layer != thin_layer) && seg_is_thin(seg)) {
+	} else if ((layer != _thin_layer) && seg_is_thin(seg)) {
 		lva = *laopts;
 		lva.real_pool = 1;
 		if (!_add_new_lv_to_dtree(dm, dtree, seg_is_thin_pool(seg) ?
-					  seg->lv : seg->pool_lv, &lva, thin_layer))
+					  seg->lv : seg->pool_lv, &lva, _thin_layer))
 			return_0;
 	} else {
 		if (seg_is_thin_pool(seg) &&