diff --git a/puppetboard/app.py b/puppetboard/app.py
index 60482b00a..a36d33805 100644
--- a/puppetboard/app.py
+++ b/puppetboard/app.py
@@ -66,6 +66,12 @@
 log = logging.getLogger(__name__)
 
 
+@app.template_filter()
+def format_attribute(obj, attr, format_str):
+    setattr(obj, attr, format_str.format(getattr(obj, attr)))
+    return obj
+
+
 def stream_template(template_name, **context):
     app.update_template_context(context)
     t = app.jinja_env.get_template(template_name)
diff --git a/puppetboard/templates/fact.json.tpl b/puppetboard/templates/fact.json.tpl
index 9e38570f3..7bd982de7 100644
--- a/puppetboard/templates/fact.json.tpl
+++ b/puppetboard/templates/fact.json.tpl
@@ -26,10 +26,10 @@
   ]
   {%- if render_graph %},
   "chart": [
-    {% for fact_h in facts | groupby('value') -%}
+    {% for fact_h in facts | map('format_attribute', 'value', '{0}') | groupby('value') -%}
     {%- if not loop.first %},{%- endif -%}
     {
-      "label": {{ fact_h.grouper.replace("\n", " ") | jsonprint }},
+      "label": {{ fact_h.grouper | replace("\n", " ") | jsonprint }},
       "value": {{ fact_h.list|length }}
     }
     {% endfor %}
diff --git a/test/test_app.py b/test/test_app.py
index 149c6b44d..e1b18aed9 100644
--- a/test/test_app.py
+++ b/test/test_app.py
@@ -637,7 +637,7 @@ def test_node_view(client, mocker,
 def test_fact_json_with_graph(client, mocker,
                               mock_puppetdb_environments,
                               mock_puppetdb_default_nodes):
-    values = ['a', 'b', 'b', 'd']
+    values = ['a', 'b', 'b', 'd', True, 'a\nb']
     query_data = {'facts': []}
     query_data['facts'].append([])
     for i, value in enumerate(values):
@@ -658,14 +658,14 @@ def test_fact_json_with_graph(client, mocker,
     result_json = json.loads(rv.data.decode('utf-8'))
 
     assert 'data' in result_json
-    assert len(result_json['data']) == 4
+    assert len(result_json['data']) == 6
     for line in result_json['data']:
         assert len(line) == 2
 
     assert 'chart' in result_json
-    assert len(result_json['chart']) == 3
+    assert len(result_json['chart']) == 5
     # Test group_by
-    assert result_json['chart'][1]['value'] == 2
+    assert result_json['chart'][3]['value'] == 2
 
 
 def test_fact_json_without_graph(client, mocker,