diff --git a/cdf_compare.py b/cdf_compare.py
index 6fc9b35..2a0c99d 100755
--- a/cdf_compare.py
+++ b/cdf_compare.py
@@ -65,7 +65,6 @@ def plot_cdf(dataframe, column_name, axis=None):
         stats_df.plot(x=column_name, y=["CDF"], grid=True, ax=axis)
     else:
         stats_df.plot(x=column_name, y=["CDF"], grid=True)
-    return axis
 
 
 if __name__ == "__main__":
@@ -190,8 +189,8 @@ if __name__ == "__main__":
         ))
 
     # Plot sRTT CDF
-    ax = plot_cdf(transmission_df_list[0]["df"], "srtt")
-    plot_cdf(transmission_df_list[1]["df"], "srtt", axis=ax)
+    plot_cdf(transmission_df_list[0]["df"], "srtt")
+    plot_cdf(transmission_df_list[1]["df"], "srtt", axis=plt.gca())
     plt.xscale("log")
     plt.xlabel("sRTT [s]")
     plt.ylabel("CDF")
@@ -202,8 +201,8 @@ if __name__ == "__main__":
     plt.clf()
 
     # Plot goodput CDF
-    ax = plot_cdf(transmission_df_list[0]["df"], "goodput")
-    plot_cdf(transmission_df_list[1]["df"], "goodput", axis=ax)
+    plot_cdf(transmission_df_list[0]["df"], "goodput")
+    plot_cdf(transmission_df_list[1]["df"], "goodput", axis=plt.gca())
     plt.xlabel("goodput [mbps]")
     plt.ylabel("CDF")
     plt.legend([transmission_df_list[0]["cc_algo"], transmission_df_list[1]["cc_algo"]])