diff --git a/README.md b/README.md
index 06bd12b..3495036 100644
--- a/README.md
+++ b/README.md
@@ -26,8 +26,8 @@ from filterdesign import filterplot
 z, p, k = emqf.analog_lowpass(order=7, stopband_attenuation=50, f3db=True)
 
 fig, (ax1, ax2) = plt.subplots(1, 2)
-filterplot.plot_analog_filter_zpk((z, p, k), ax=ax[0])
-filterplot.pole_zero_plot((z, p, k), unitcircle=True, ax=ax[1])
+filterplot.plot_analog_filter_zpk((z, p, k), ax=ax1)
+filterplot.pole_zero_plot((z, p, k), unitcircle=True, ax=ax2)
 plt.show()
 ```
 
diff --git a/examples/freq_response.py b/examples/freq_response.py
index 74682e5..3787dc7 100644
--- a/examples/freq_response.py
+++ b/examples/freq_response.py
@@ -21,9 +21,9 @@
 fig_.tight_layout()
 
 
-fig, ax = plt.subplots(1, 2)
-filterplot.plot_analog_filter_zpk((z, p, k), ax=ax[0])
-filterplot.pole_zero_plot((z, p, k), unitcircle=True, ax=ax[1])
+fig, (ax1, ax2) = plt.subplots(1, 2)
+filterplot.plot_analog_filter_zpk((z, p, k), ax=ax1)
+filterplot.pole_zero_plot((z, p, k), unitcircle=True, ax=ax2)
 # ax2.scatter(0, 1)
 
 fig_.savefig("./examples/img/emqf_freq_zpk.png", dpi=200)