diff --git a/tests/test_filesize.py b/tests/test_filesize.py
index 937ef735..b8f9163a 100644
--- a/tests/test_filesize.py
+++ b/tests/test_filesize.py
@@ -7,6 +7,11 @@ def test_traditional():
     assert filesize.decimal(2) == "2 bytes"
     assert filesize.decimal(1000) == "1.0 kB"
     assert filesize.decimal(1.5 * 1000 * 1000) == "1.5 MB"
+    assert filesize.decimal(0, precision=2) == "0 bytes"
+    assert filesize.decimal(1111, precision=0) == "1 kB"
+    assert filesize.decimal(1111, precision=1) == "1.1 kB"
+    assert filesize.decimal(1111, precision=2) == "1.11 kB"
+    assert filesize.decimal(1111, separator="") == "1.1kB"
 
 
 def test_pick_unit_and_suffix():