diff --git a/holoviews/tests/element/test_annotations.py b/holoviews/tests/element/test_annotations.py
index 153feb4643..f8cdc6dc01 100644
--- a/holoviews/tests/element/test_annotations.py
+++ b/holoviews/tests/element/test_annotations.py
@@ -13,7 +13,7 @@ class AnnotationTests(ComparisonTestCase):
     """
 
     def test_hline_invalid_constructor(self):
-        err = "ClassSelector parameter 'y' value must be an instance of"
+        err = "ClassSelector parameter 'HLine.y' value must be an instance of"
         with pytest.raises(ValueError) as excinfo:
             HLine(None)
         assert err in str(excinfo.value)
diff --git a/holoviews/tests/test_streams.py b/holoviews/tests/test_streams.py
index 9031709c29..15ee847097 100644
--- a/holoviews/tests/test_streams.py
+++ b/holoviews/tests/test_streams.py
@@ -71,24 +71,24 @@ def test_XY_instance(self):
         self.assertEqual(xy.y, 2)
 
     def test_XY_set_invalid_class_x(self):
-        regexp = "Parameter 'x' only takes numeric values"
+        regexp = "Number parameter 'XY.x' only takes numeric values"
         with self.assertRaisesRegex(ValueError, regexp):
             self.XY.x = 'string'
 
     def test_XY_set_invalid_class_y(self):
-        regexp = "Parameter 'y' only takes numeric values"
+        regexp = "Number parameter 'XY.y' only takes numeric values"
         with self.assertRaisesRegex(ValueError, regexp):
             self.XY.y = 'string'
 
     def test_XY_set_invalid_instance_x(self):
         xy = self.XY(x=1,y=2)
-        regexp = "Parameter 'x' only takes numeric values"
+        regexp = "Number parameter 'XY.x' only takes numeric values"
         with self.assertRaisesRegex(ValueError, regexp):
             xy.x = 'string'
 
     def test_XY_set_invalid_instance_y(self):
         xy = self.XY(x=1,y=2)
-        regexp = "Parameter 'y' only takes numeric values"
+        regexp = "Number parameter 'XY.y' only takes numeric values"
         with self.assertRaisesRegex(ValueError, regexp):
             xy.y = 'string'