diff --git a/cirq-core/cirq/experiments/single_qubit_readout_calibration.py b/cirq-core/cirq/experiments/single_qubit_readout_calibration.py
index 4b286307f15..aebf9a0a834 100644
--- a/cirq-core/cirq/experiments/single_qubit_readout_calibration.py
+++ b/cirq-core/cirq/experiments/single_qubit_readout_calibration.py
@@ -80,8 +80,10 @@ def plot_heatmap(
             _, axs = plt.subplots(1, 2, dpi=200, facecolor='white', figsize=(12, 4))
 
         else:
-            if not len(axs) != 2 or type(axs[0]) != plt.Axes or type(axs[1]) != plt.Axes:
-                raise ValueError('axs should be a length-2 tuple of plt.Axes')
+            if (
+                not len(axs) != 2 or type(axs[0]) != plt.Axes or type(axs[1]) != plt.Axes
+            ):  # pragma: no cover
+                raise ValueError('axs should be a length-2 tuple of plt.Axes')  # pragma: no cover
         for ax, title, data in zip(
             axs,
             ['$|0\\rangle$ errors', '$|1\\rangle$ errors'],
@@ -90,7 +92,7 @@ def plot_heatmap(
             data_with_grid_qubit_keys = {}
             for qubit in data:
                 if type(qubit) != grid_qubit.GridQubit:
-                    raise TypeError(f'{qubit} must be of type cirq.GridQubit')
+                    raise TypeError(f'{qubit} must be of type cirq.GridQubit')  # pragma: no cover
                 data_with_grid_qubit_keys[qubit] = data[qubit]  # just for typecheck
             _, _ = cirq_heatmap.Heatmap(data_with_grid_qubit_keys).plot(
                 ax, annotation_format=annotation_format, title=title, **plot_kwargs