diff --git a/tests/test_cidr4_merger.py b/tests/test_cidr4_merger.py
index 58e89d4..18af387 100644
--- a/tests/test_cidr4_merger.py
+++ b/tests/test_cidr4_merger.py
@@ -1,23 +1,11 @@
 import pytest
 
-from cidr4_merger import (
-    Cidr4MergerError,
-    cidr4_to_node,
-    find_neighbours_singles,
-    get_group_with_max_mask_len,
-    get_net_addr,
-    get_parent_ip,
-    have_same_parent,
-    lift_lonely_node,
-    make_cidr4,
-    make_groups,
-    make_parent,
-    merge_neighbors,
-    merge_nodes,
-    merge_nodes_recursion,
-    reduce_nodes,
-    sort_nodes,
-)
+from cidr4_merger import (Cidr4MergerError, cidr4_to_node,
+                          find_neighbours_singles, get_group_with_max_mask_len,
+                          get_net_addr, get_parent_ip, have_same_parent,
+                          lift_lonely_node, make_cidr4, make_groups,
+                          make_parent, merge_neighbors, merge_nodes,
+                          merge_nodes_recursion, reduce_nodes, sort_nodes)
 
 
 def test_true():
@@ -210,21 +198,23 @@ def test_merge_nodes():
 
 
 def test_make_groups():
-    groups = make_groups(
-        [
-            (0, 2, 12, 0),
-            (1073741824, 2, 3, 0),
-            (2147483648, 2, 1, 2147483648),
-            (3221225472, 2, 2, 2147483648),
-        ]
-    )
-    assert dict(groups) == {
-        2: [
-            (0, 2, 12, 0),
-            (1073741824, 2, 3, 0),
-            (2147483648, 2, 1, 2147483648),
-            (3221225472, 2, 2, 2147483648),
-        ]
+    nodes = [
+        (2398793728, 20, 0, 2398789632),
+        (2899943424, 20, 0, 2899943424),
+        (3627728896, 20, 0, 3627728896),
+        (520963072, 22, 0, 520962048),
+        (1089054720, 22, 0, 1089054720),
+        (2899902464, 19, 0, 2899902464),
+        (2915221504, 19, 0, 2915221504),
+    ]
+    assert dict(make_groups(nodes)) == {
+        20: [
+            (2398793728, 20, 0, 2398789632),
+            (2899943424, 20, 0, 2899943424),
+            (3627728896, 20, 0, 3627728896),
+        ],
+        22: [(520963072, 22, 0, 520962048), (1089054720, 22, 0, 1089054720)],
+        19: [(2899902464, 19, 0, 2899902464), (2915221504, 19, 0, 2915221504)],
     }