diff --git a/src/uwtools/drivers/driver.py b/src/uwtools/drivers/driver.py
index 35fd3c7d3..bfc6d1d02 100644
--- a/src/uwtools/drivers/driver.py
+++ b/src/uwtools/drivers/driver.py
@@ -112,7 +112,7 @@ def schema(cls) -> dict:
         with open(internal_schema_file(schema_name=cls._schema_name()), "r", encoding="utf-8") as f:
             return bundle(json.load(f))
 
-    def taskname(self, suffix: str) -> str:
+    def taskname(self, suffix: Optional[str] = None) -> str:
         """
         Return a common tag for task-related log messages.
 
diff --git a/src/uwtools/drivers/make_solo_mosaic.py b/src/uwtools/drivers/make_solo_mosaic.py
index d9598edac..86efcadd0 100644
--- a/src/uwtools/drivers/make_solo_mosaic.py
+++ b/src/uwtools/drivers/make_solo_mosaic.py
@@ -2,6 +2,8 @@
 A driver for make_solo_mosaic.
 """
 
+from typing import Optional
+
 from iotaa import tasks
 
 from uwtools.drivers.driver import DriverTimeInvariant
@@ -26,7 +28,7 @@ def provisioned_rundir(self):
 
     # Public helper methods
 
-    def taskname(self, suffix: str) -> str:
+    def taskname(self, suffix: Optional[str] = None) -> str:
         """
         Return a common tag for graph-task log messages.
 
diff --git a/src/uwtools/tests/drivers/test_driver.py b/src/uwtools/tests/drivers/test_driver.py
index 1553d699d..5b6a66edf 100644
--- a/src/uwtools/tests/drivers/test_driver.py
+++ b/src/uwtools/tests/drivers/test_driver.py
@@ -233,6 +233,11 @@ def test_Assets_leadtime(config):
     assert obj.leadtime == leadtime
 
 
+def test_Assets_taskname(assetsobj):
+    assert assetsobj.taskname() == "concrete"
+    assert assetsobj.taskname(suffix="test") == "concrete test"
+
+
 def test_Assets_validate(assetsobj, caplog):
     log.setLevel(logging.INFO)
     assetsobj.validate()
diff --git a/src/uwtools/tests/drivers/test_support.py b/src/uwtools/tests/drivers/test_support.py
index 474382db0..8c17171d8 100644
--- a/src/uwtools/tests/drivers/test_support.py
+++ b/src/uwtools/tests/drivers/test_support.py
@@ -48,7 +48,7 @@ def driver_name(cls):
         def provisioned_rundir(self):
             pass
 
-        def taskname(self, suffix):
+        def taskname(self, suffix=None):
             pass
 
         @external