diff --git a/charon_vna/gui.py b/charon_vna/gui.py
index 22f0b0f..fe16b31 100644
--- a/charon_vna/gui.py
+++ b/charon_vna/gui.py
@@ -49,7 +49,9 @@ class PlotWidget(QWidget):
         self.fig = plt.Figure(figsize=(5, 4), dpi=100, tight_layout=True)
         self.ax = self.fig.add_subplot(111)
         self.set_plot_type(type_)
-        self.lines = [self.ax.plot([np.nan], [np.nan], label="$S_{" + str(m) + str(n) + "}$") for m, n in self.traces]
+        self.lines = [
+            self.ax.plot([np.nan], [np.nan], label="$S_{" + str(m) + str(n) + "}$")[0] for m, n in self.traces
+        ]
         self.ax.legend(loc="upper right")
 
         canvas = FigureCanvasQTAgg(self.fig)
@@ -97,14 +99,11 @@ class PlotWidget(QWidget):
 
     def update_rect(self, data: xr.DataArray, func: Callable[[npt.ArrayLike], npt.ArrayLike]) -> None:
         self.ax.set_xlim(data["frequency"].min().data, data["frequency"].max().data)
-        # remove old lines
-        for line in self.ax.lines:
-            line.remove()
         for ii, (m, n) in enumerate(self.traces):
-            self.lines[ii] = self.ax.plot(data["frequency"], func(data.sel(m=m, n=n)))[0]
+            self.lines[ii].set_xdata(data["frequency"])
+            self.lines[ii].set_ydata(func(data.sel(m=m, n=n)))
 
         self.fig.canvas.draw()
-        self.fig.canvas.flush_events()
 
     def setup_logmag(self, ylim: List[float] = [-30, 30]) -> None:
         self.setup_rect()
@@ -139,15 +138,12 @@ class PlotWidget(QWidget):
         rf_plt.smith(ax=self.ax, smithR=1, chart_type="z", draw_vswr=None)
 
     def update_smith(self, data: xr.DataArray) -> None:
-        # remove old lines
-        for line in self.ax.lines:
-            line.remove()
         for ii, (m, n) in enumerate(self.traces):
             sel = data.sel(m=m, n=n)
-            self.lines[ii] = self.ax.plot(sel.real, sel.imag)[0]
+            self.lines[ii].set_xdata(sel.real)
+            self.lines[ii].set_ydata(sel.imag)
 
         self.fig.canvas.draw()
-        self.fig.canvas.flush_events()
 
 
 # Subclass QMainWindow to customize your application's main window