diff --git a/combo/apps/dataviz/models.py b/combo/apps/dataviz/models.py
index 085edc0d..65cbe683 100644
--- a/combo/apps/dataviz/models.py
+++ b/combo/apps/dataviz/models.py
@@ -207,6 +207,9 @@ class ChartNgCell(CellBase):
                 y_labels = loop_labels
             else:
                 x_labels, y_labels = y_labels, loop_labels
+            if len(y_labels) != len(data) or not all([len(x) == len(x_labels) for x in data]):
+                # varying dimensions
+                raise UnsupportedDataSet()
         if not x_labels and not y_labels:  # unidata
             x_labels = ['']
             y_labels = ['']
diff --git a/tests/test_dataviz.py b/tests/test_dataviz.py
index 363acdc5..21f2c27a 100644
--- a/tests/test_dataviz.py
+++ b/tests/test_dataviz.py
@@ -94,6 +94,12 @@ VISUALIZATION_JSON = [
         'name': 'eighth visualization (duration)',
         'slug': 'eighth',
     },
+    {
+        'data-url': 'https://bijoe.example.com/visualization/9/json/',
+        'path': 'https://bijoe.example.com/visualization/9/iframe/?signature=123',
+        'name': 'nineth visualization (loop over varying dimensions)',
+        'slug': 'nineth',
+    },
 ]
 
 
@@ -190,6 +196,20 @@ def bijoe_mock(url, request):
             'unit': 'seconds',
         }
         return {'content': json.dumps(response), 'request': request, 'status_code': 200}
+    if url.path == '/visualization/9/json/':
+        response = {
+            'format': '1',
+            'data': [
+                [1, 1, 1, 1],
+                [1],
+                [1, 1],
+            ],
+            'axis': {
+                'y_labels': ['web', 'mail', 'email'],
+                'loop': ['a', 'b', 'c', 'd'],
+            }
+        }
+        return {'content': json.dumps(response), 'request': request, 'status_code': 200}
 
 
 def test_chartng_cell(app):
@@ -293,6 +313,12 @@ def test_chartng_cell(app):
             cell.save()
             chart = cell.get_chart()
 
+            # loop/X/Y
+            cell.data_reference = 'plop:nineth'
+            cell.save()
+            with pytest.raises(UnsupportedDataSet):
+                chart = cell.get_chart()
+
 
 def test_chartng_cell_view(app, normal_user):
     page = Page(title='One', slug='index')
@@ -390,6 +416,7 @@ def test_chartng_cell_manager(app, admin_user):
                 (u'plop:example', True, u'example visualization (X)'),
                 (u'plop:fifth', False, u'fifth visualization (loop/X)'),
                 (u'plop:fourth', False, u'fourth visualization (no axis)'),
+                (u'plop:nineth', False, u'nineth visualization (loop over varying dimensions)'),
                 (u'plop:second', False, u'second visualization (Y)'),
                 (u'plop:seventh', False, u'seventh visualization (loop/X/Y)'),
                 (u'plop:sixth', False, u'sixth visualization (loop/Y)'),