diff --git a/artiq/applets/plot_hist.py b/artiq/applets/plot_hist.py
index 9dbebcf4c..3be604930 100755
--- a/artiq/applets/plot_hist.py
+++ b/artiq/applets/plot_hist.py
@@ -15,13 +15,13 @@ class HistogramPlot(pyqtgraph.PlotWidget):
         self.timer.setSingleShot(True)
         self.timer.timeout.connect(self.length_warning)
 
-    def data_changed(self, data, mods, title):
+    def data_changed(self, value, metadata, persist, mods, title):
         try:
-            y = data[self.args.y][1]
+            y = value[self.args.y]
             if self.args.x is None:
                 x = None
             else:
-                x = data[self.args.x][1]
+                x = value[self.args.x]
         except KeyError:
             return
         if x is None: