diff --git a/kwant/tests/test_builder.py b/kwant/tests/test_builder.py
index fc9a052f1a586dcca6bc50d6397da0da9ef49316..46b3faeed6a81ff53ab3073da269959e40ad33d9 100644
--- a/kwant/tests/test_builder.py
+++ b/kwant/tests/test_builder.py
@@ -863,18 +863,20 @@ def test_dangling():
             sorted(site.tag for site in syst1.sites()))
 
 def test_dangling_with_symmetry():
-    length = 3
-    symm = kwant.TranslationalSymmetry((length, 0))
-    lat = kwant.lattice.square(norbs=1)
-    syst = kwant.Builder(symmetry=symm)
-    for x in range(length):
-        syst[lat(x, 0)] = 0
-        syst[lat(x, 1)] = 0
-    syst[lat.neighbors()] = -1
-    # remove neighbors of site at (lenght-1, 0), dangling across symm
-    del syst[lat(length - 2, 0)]
-    del syst[lat(length - 1, 1)]
-    syst.eradicate_dangling()
+    # lenght = 3 is the special case that gives all dangling bonds
+    # lenght = 4 is the standard case of dangling bonds across the symmetry
+    for length in [3, 4]:
+        symm = kwant.TranslationalSymmetry((length, 0))
+        lat = kwant.lattice.square(norbs=1)
+        syst = kwant.Builder(symmetry=symm)
+        for x in range(length):
+            syst[lat(x, 0)] = 0
+            syst[lat(x, 1)] = 0
+        syst[lat.neighbors()] = -1
+        # remove neighbors of site at (lenght-1, 0), dangling across symm
+        del syst[lat(length - 2, 0)]
+        del syst[lat(length - 1, 1)]
+        syst.eradicate_dangling()
 
 def test_builder_with_symmetry():
     g = kwant.lattice.general(ta.identity(3), norbs=1)