diff --git a/holoviews/plotting/bokeh/element.py b/holoviews/plotting/bokeh/element.py
index b1346e73ae..7c247b081c 100644
--- a/holoviews/plotting/bokeh/element.py
+++ b/holoviews/plotting/bokeh/element.py
@@ -1186,14 +1186,14 @@ def _get_color_data(self, element, ranges, style, name='color', factors=None, co
         if factors is None and (isinstance(cdata, list) or cdata.dtype.kind in dtypes):
             factors = list(util.unique_array(cdata))
         if factors and int_categories and cdata.dtype.kind == 'i':
-            field += '_str'
+            field += '_str__'
             cdata = [str(f) for f in cdata]
             factors = [str(f) for f in factors]
 
         mapper = self._get_colormapper(cdim, element, ranges, style,
                                        factors, colors)
         if not factors and isinstance(mapper, CategoricalColorMapper):
-            field += '_str'
+            field += '_str__'
             cdata = [cdim.pprint_value(c) for c in cdata]
             factors = mapper.factors
 
diff --git a/holoviews/tests/plotting/bokeh/testelementplot.py b/holoviews/tests/plotting/bokeh/testelementplot.py
index 4f6694ac68..aad836e4c0 100644
--- a/holoviews/tests/plotting/bokeh/testelementplot.py
+++ b/holoviews/tests/plotting/bokeh/testelementplot.py
@@ -241,7 +241,7 @@ def test_explicit_categorical_cmap_on_integer_data(self):
         plot = bokeh_renderer.get_plot(points)
         cmapper = plot.handles['color_mapper']
         cds = plot.handles['cds']
-        self.assertEqual(cds.data['Category_str'], ['0', '1', '2', '3'])
+        self.assertEqual(cds.data['Category_str__'], ['0', '1', '2', '3'])
         self.assertEqual(cmapper.factors, ['0', '1', '2', '3'])
         self.assertEqual(cmapper.palette, ['blue', 'red', 'green', 'purple'])
 
diff --git a/holoviews/tests/plotting/bokeh/testgraphplot.py b/holoviews/tests/plotting/bokeh/testgraphplot.py
index bcf672b414..f316119a3b 100644
--- a/holoviews/tests/plotting/bokeh/testgraphplot.py
+++ b/holoviews/tests/plotting/bokeh/testgraphplot.py
@@ -142,8 +142,8 @@ def test_graph_edges_categorical_colormapped(self):
         self.assertIsInstance(cmapper, CategoricalColorMapper)
         factors = ['0', '1', '2', '3', '4', '5', '6', '7']
         self.assertEqual(cmapper.factors, factors)
-        self.assertEqual(edge_source.data['start_str'], factors)
-        self.assertEqual(glyph.line_color, {'field': 'start_str', 'transform': cmapper})
+        self.assertEqual(edge_source.data['start_str__'], factors)
+        self.assertEqual(glyph.line_color, {'field': 'start_str__', 'transform': cmapper})
 
     def test_graph_edges_numerically_colormapped(self):
         g = self.graph4.opts(plot=dict(edge_color_index='Weight'),
@@ -202,8 +202,8 @@ def test_graph_edges_categorical_colormapped(self):
         self.assertIsInstance(cmapper, CategoricalColorMapper)
         factors = ['0', '1', '2', '3']
         self.assertEqual(cmapper.factors, factors)
-        self.assertEqual(edge_source.data['node1_str'], ['0', '1'])
-        self.assertEqual(glyph.line_color, {'field': 'node1_str', 'transform': cmapper})
+        self.assertEqual(edge_source.data['node1_str__'], ['0', '1'])
+        self.assertEqual(glyph.line_color, {'field': 'node1_str__', 'transform': cmapper})
 
     def test_graph_nodes_numerically_colormapped(self):
         g = self.trimesh_weighted.opts(plot=dict(edge_color_index='weight'),
@@ -258,6 +258,6 @@ def test_chord_edges_categorically_colormapped(self):
         self.assertIsInstance(cmapper, CategoricalColorMapper)
         self.assertEqual(cmapper.palette, ['#FFFFFF', '#000000', '#FFFFFF'])
         self.assertEqual(cmapper.factors, ['0', '1', '2'])
-        self.assertEqual(edge_source.data['start_str'], ['0', '0', '1'])
-        self.assertEqual(glyph.line_color, {'field': 'start_str', 'transform': cmapper})
+        self.assertEqual(edge_source.data['start_str__'], ['0', '0', '1'])
+        self.assertEqual(glyph.line_color, {'field': 'start_str__', 'transform': cmapper})