diff --git a/tests/test_filesize.py b/tests/test_filesize.py
index 645751b9..6a8e4f14 100644
--- a/tests/test_filesize.py
+++ b/tests/test_filesize.py
@@ -74,10 +74,10 @@
         ([3000, False, True, "%.3f"], "2.930K"),
         ([3000000000, False, True, "%.0f"], "3G"),
         ([10**26 * 30, True, False, "%.3f"], "2.423 RiB"),
-        ([1.123456789], "1 Bytes"),
+        ([1.123456789], "1.1 Bytes"),
         ([1.123456789 * 10**3], "1.1 kB"),
         ([1.123456789 * 10**6], "1.1 MB"),
-        ([1.123456789, False, True], "1B"),
+        ([1.123456789, False, True], "1.1B"),
         ([1.123456789 * 10**3, False, True], "1.1K"),
         ([1.123456789 * 10**6, False, True], "1.1M"),
         # Rounding must not leave the mantissa at the base while a larger suffix
@@ -89,6 +89,30 @@
         ([1024**2 - 1, True], "1.0 MiB"),
         ([1024**3 - 1, True], "1.0 GiB"),
         ([1024**2 - 1, False, True], "1.0M"),
+        ([1.5], "1.5 Bytes"),
+        ([1.9], "1.9 Bytes"),
+        ([0.5], "0.5 Bytes"),
+        (["1.5"], "1.5 Bytes"),
+        ([999.5], "999.5 Bytes"),
+        ([999.94], "999.9 Bytes"),
+        ([1.5, True], "1.5 Bytes"),
+        ([1.123456789, True], "1.1 Bytes"),
+        ([1023.5, True], "1023.5 Bytes"),
+        ([1.5, False, True], "1.5B"),
+        ([1023.5, False, True], "1023.5B"),
+        ([1.25, False, False, "%.2f"], "1.25 Bytes"),
+        ([1.5, False, True, "%.3f"], "1.500B"),
+        ([2.04], "2.0 Bytes"),
+        ([1.04], "1.0 Bytes"),
+        ([0.96], "1.0 Bytes"),
+        ([2.0], "2 Bytes"),
+        ([999], "999 Bytes"),
+        ([999.0], "999 Bytes"),
+        ([1023, True], "1023 Bytes"),
+        ([1023, False, True], "1023B"),
+        ([300, False, False, "%.3f"], "300 Bytes"),
+        ([300, False, True, "%.3f"], "300B"),
+        ([1.0, False, False, "%.3f"], "1 Byte"),
     ],
 )
 def test_naturalsize(test_args: list[int] | list[int | bool], expected: str) -> None: