diff --git a/Orange/widgets/tests/base.py b/Orange/widgets/tests/base.py
index 07ffa7715e4..247b7aa2292 100644
--- a/Orange/widgets/tests/base.py
+++ b/Orange/widgets/tests/base.py
@@ -730,6 +730,21 @@ def test_send_report(self, timeout=DEFAULT_TIMEOUT):
         self.send_signal(self.widget.Inputs.data, None)
         self.widget.report_button.click()
 
+    def test_hidden_effective_variables(self, timeout=DEFAULT_TIMEOUT):
+        hidden_var1 = ContinuousVariable("c1")
+        hidden_var1.attributes["hidden"] = True
+        hidden_var2 = ContinuousVariable("c2")
+        hidden_var2.attributes["hidden"] = True
+        class_vars = [DiscreteVariable("cls", values=["a", "b"])]
+        table = Table(Domain([hidden_var1, hidden_var2], class_vars),
+                      np.array([[0., 1.], [2., 3.]]),
+                      np.array([[0.], [1.]]))
+        self.send_signal(self.widget.Inputs.data, table)
+        if self.widget.isBlocking():
+            spy = QSignalSpy(self.widget.blockingStateChanged)
+            self.assertTrue(spy.wait(timeout))
+        self.send_signal(self.widget.Inputs.data, table)
+
 
 class AnchorProjectionWidgetTestMixin(ProjectionWidgetTestMixin):
     def test_embedding_missing_values(self):
diff --git a/Orange/widgets/visualize/owscatterplot.py b/Orange/widgets/visualize/owscatterplot.py
index dd6f04ec11c..8aeaecfc770 100644
--- a/Orange/widgets/visualize/owscatterplot.py
+++ b/Orange/widgets/visualize/owscatterplot.py
@@ -297,7 +297,7 @@ def _add_controls_sampling(self):
 
     @property
     def effective_variables(self):
-        return [self.attr_x, self.attr_y]
+        return [self.attr_x, self.attr_y] if self.attr_x and self.attr_y else []
 
     def _vizrank_color_change(self):
         self.vizrank.initialize()
diff --git a/Orange/widgets/visualize/tests/test_owscatterplot.py b/Orange/widgets/visualize/tests/test_owscatterplot.py
index f088abfd3f4..4d57f48e963 100644
--- a/Orange/widgets/visualize/tests/test_owscatterplot.py
+++ b/Orange/widgets/visualize/tests/test_owscatterplot.py
@@ -634,7 +634,7 @@ def test_invalidated_features_first(self):
         # send features (same as default ones)
         self.send_signal(self.widget.Inputs.features,
                          AttributeList(self.data.domain.attributes[:2]))
-        self.assertListEqual(self.widget.effective_variables, [None, None])
+        self.assertListEqual(self.widget.effective_variables, [])
         self.widget.setup_plot.assert_called_once()
 
         # send data
@@ -685,7 +685,7 @@ def test_invalidated_diff_features_features_first(self):
         # send features (not the same as defaults)
         self.send_signal(self.widget.Inputs.features,
                          AttributeList(self.data.domain.attributes[2:4]))
-        self.assertListEqual(self.widget.effective_variables, [None, None])
+        self.assertListEqual(self.widget.effective_variables, [])
         self.widget.setup_plot.assert_called_once()
 
         # send data