diff --git a/CHANGES.rst b/CHANGES.rst
index b3e0629b3..4f156f933 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -24,8 +24,10 @@ Release history
 **Fixed**
 
 - Support Sparse transforms in ``Simulator.get_nengo_params``. (`#149`_)
+- Fixed bug in TensorGraph log message when logging was enabled. (`#151`_)
 
 .. _#149: https://github.com/nengo/nengo-dl/pull/149
+.. _#151: https://github.com/nengo/nengo-dl/pull/151
 
 3.2.0 (April 2, 2020)
 ---------------------
diff --git a/nengo_dl/tensor_graph.py b/nengo_dl/tensor_graph.py
index 12a853299..25a0dde79 100644
--- a/nengo_dl/tensor_graph.py
+++ b/nengo_dl/tensor_graph.py
@@ -174,7 +174,7 @@ def __init__(
         logger.info("Optimized plan length: %d", len(self.plan))
         logger.info(
             "Number of base arrays: (%s, %d), (%s, %d), (%s, %d)",
-            *tuple((k, len(x)) for k, x in self.base_arrays_init.items()),
+            *sum(((k, len(x)) for k, x in self.base_arrays_init.items()), ()),
         )
 
     def build_inputs(self):
diff --git a/nengo_dl/tests/test_simulator.py b/nengo_dl/tests/test_simulator.py
index a96fecaf1..c84654e27 100644
--- a/nengo_dl/tests/test_simulator.py
+++ b/nengo_dl/tests/test_simulator.py
@@ -1822,3 +1822,16 @@ def test_sim_close(Simulator):
     with pytest.raises(SimulatorClosed, match="simulator is closed"):
         with sim:
             pass
+
+
+def test_logging(Simulator, caplog):
+    with nengo.Network() as net:
+        inp = nengo.Node([0])
+        ens = nengo.Ensemble(10, 1)
+        nengo.Connection(inp, ens)
+        nengo.Probe(ens)
+
+    # run a simulation with logging to verify that there are no errors
+    with caplog.at_level(logging.NOTSET):
+        with Simulator(net) as sim:
+            sim.run_steps(10)