diff --git a/tests/test_relabel.py b/tests/test_relabel.py
index 6366b83..8eacbe7 100644
--- a/tests/test_relabel.py
+++ b/tests/test_relabel.py
@@ -11,6 +11,57 @@
 logging.disable(logging.CRITICAL)
 
 
+# ------------------------------------------------------------------------------
+@pytest.mark.usefixtures(
+    "data_dir",
+)
+def test_relabel_darknet(
+        data_dir,
+):
+    """
+    Test for the cvdata.relabel.relabel_darknet() function
+
+    :param data_dir: temporary directory into which test files will be loaded
+    """
+    darknet_file_name = "darknet_1.txt"
+    darknet_file_path = str(data_dir.join(darknet_file_name))
+
+    # confirm that a relabeling won't occur if the old value is not present
+    relabel.relabel_darknet(darknet_file_path, 58, 59)
+    expected_darknet_file_name = "expected_darknet_1.txt"
+    expected_darknet_file_path = str(data_dir.join(expected_darknet_file_name))
+    assert text_files_equal(
+        darknet_file_path,
+        expected_darknet_file_path,
+    )
+
+    # confirm that relabeling occurred as expected
+    relabel.relabel_darknet(darknet_file_path, 3, 2)
+    expected_darknet_file_name = "expected_darknet_2.txt"
+    expected_darknet_file_path = str(data_dir.join(expected_darknet_file_name))
+    assert text_files_equal(
+        darknet_file_path,
+        expected_darknet_file_path,
+    )
+
+    # confirm that various invalid arguments raise an error
+    with pytest.raises(TypeError):
+        relabel.relabel_darknet(darknet_file_path, None, 0)
+        relabel.relabel_darknet(darknet_file_path, 0, None)
+        relabel.relabel_darknet(1, 0, 1)
+        relabel.relabel_darknet(None, 1, 0)
+        relabel.relabel_darknet("/not/present", 0, 1)
+        relabel.relabel_darknet(1.0, "strings won't work", 0)
+        relabel.relabel_darknet(darknet_file_path, 1, "strings won't work")
+        relabel.relabel_darknet(darknet_file_path, 1.0, 0)
+        relabel.relabel_darknet(darknet_file_path, 2, 1.0)
+        relabel.relabel_darknet(darknet_file_path, True, 0)
+        relabel.relabel_darknet(darknet_file_path, 1, True)
+    with pytest.raises(ValueError):
+        relabel.relabel_darknet(darknet_file_path, -5, 1)
+        relabel.relabel_darknet(darknet_file_path, 1, -4)
+
+
 # ------------------------------------------------------------------------------
 @pytest.mark.usefixtures(
     "data_dir",
@@ -44,7 +95,7 @@ def test_relabel_kitti(
         expected_kitti_file_path,
     )
 
-    # confirm that invalid argument types raise an error
+    # confirm that various invalid arguments raise an error
     with pytest.raises(ValueError):
         relabel.relabel_kitti(None, "don't care", "don't care")
         relabel.relabel_kitti(kitti_file_path, None, "don't care")
@@ -95,7 +146,7 @@ def test_relabel_pascal(
         etree_after_relabel.getroot(),
     )
 
-    # confirm that invalid argument types raise an error
+    # confirm that various invalid arguments raise an error
     with pytest.raises(ValueError):
         relabel.relabel_pascal(None, "don't care", "don't care")
         relabel.relabel_pascal(pascal_file_path, None, "don't care")
diff --git a/tests/test_relabel/darknet_1.txt b/tests/test_relabel/darknet_1.txt
new file mode 100644
index 0000000..d92d548
--- /dev/null
+++ b/tests/test_relabel/darknet_1.txt
@@ -0,0 +1 @@
+3 0.4995 0.2012 0.3994 0.0456
diff --git a/tests/test_relabel/expected_darknet_1.txt b/tests/test_relabel/expected_darknet_1.txt
new file mode 100644
index 0000000..d92d548
--- /dev/null
+++ b/tests/test_relabel/expected_darknet_1.txt
@@ -0,0 +1 @@
+3 0.4995 0.2012 0.3994 0.0456
diff --git a/tests/test_relabel/expected_darknet_2.txt b/tests/test_relabel/expected_darknet_2.txt
new file mode 100644
index 0000000..4b5c22a
--- /dev/null
+++ b/tests/test_relabel/expected_darknet_2.txt
@@ -0,0 +1 @@
+2 0.4995 0.2012 0.3994 0.0456