diff --git a/stestr/tests/test_subunit_trace.py b/stestr/tests/test_subunit_trace.py
index 203f1ec..d967e45 100644
--- a/stestr/tests/test_subunit_trace.py
+++ b/stestr/tests/test_subunit_trace.py
@@ -22,7 +22,7 @@
 from ddt import data
 from ddt import ddt
 from ddt import unpack
-from subunit.iso8601 import UTC
+from iso8601 import UTC
 from subunit.v2 import StreamResultToBytes
 
 from stestr import subunit_trace
diff --git a/test-requirements.txt b/test-requirements.txt
index 8073abf..d40dc1b 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -6,5 +6,6 @@ hacking<3.2.0,>=3.1.0
 sphinx>2.1.0 # BSD
 coverage>=4.0 # Apache-2.0
 ddt>=1.0.1 # MIT
+iso8601 # MIT
 doc8>=0.8.0 # Apache-2.0
 black~=22.0