diff --git a/grafana_dashboards/schema/panel/graph.py b/grafana_dashboards/schema/panel/graph.py
index 4d18bb4..c24f235 100644
--- a/grafana_dashboards/schema/panel/graph.py
+++ b/grafana_dashboards/schema/panel/graph.py
@@ -1,3 +1,5 @@
+# -*- coding: utf-8 -*-
+
 # Copyright 2015 Red Hat, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -20,6 +22,68 @@ from grafana_dashboards.schema.panel.base import Base
 class Graph(Base):
 
     def get_schema(self):
+        y_format = v.Any(
+            u'none',
+            u'short',
+            u'percent',
+            u'percentunit',
+            u'humidity',
+            u'ppm',
+            u'dB',
+            u'currencyUSD',
+            u'currencyGBP',
+            u'currencyEUR',
+            u'currencyJPY',
+            u'hertz',
+            u'ns',
+            u'µs',
+            u'ms',
+            u's',
+            u'm',
+            u'h',
+            u'd',
+            u'bits',
+            u'bytes',
+            u'kbytes',
+            u'mbytes',
+            u'gbytes',
+            u'pps',
+            u'bps',
+            u'Bps',
+            u'ops',
+            u'rps',
+            u'wps',
+            u'iops',
+            u'lengthmm',
+            u'lengthm',
+            u'lengthkm',
+            u'lengthmi',
+            u'velocityms',
+            u'velocitykmh',
+            u'velocitymph',
+            u'velocityknot',
+            u'mlitre',
+            u'litre',
+            u'm3',
+            u'watt',
+            u'kwatt',
+            u'watth',
+            u'kwatth',
+            u'joule',
+            u'ev',
+            u'amp',
+            u'volt',
+            u'celsius',
+            u'farenheit',
+            u'kelvin',
+            u'pressurembar',
+            u'pressurehpa',
+            u'pressurehg',
+            u'pressurepsi',
+        )
+
+        y_formats = [y_format]
+
         graph = {
             v.Required('bars', default=False): v.All(bool),
             v.Required('fill', default=1): v.All(int),
@@ -35,6 +99,7 @@ class Graph(Base):
             v.Required('y-axis', default=True): v.All(bool),
             v.Optional('leftYAxisLabel'): v.All(str, v.Length(min=1)),
             v.Optional('rightYAxisLabel'): v.All(str, v.Length(min=1)),
+            v.Optional('y_formats'): v.All(y_formats, v.Length(min=2, max=2)),
         }
         graph.update(self.base)
         return v.Schema(graph)
diff --git a/tests/schema/fixtures/dashboard-0010.json b/tests/schema/fixtures/dashboard-0010.json
new file mode 100644
index 0000000..8944003
--- /dev/null
+++ b/tests/schema/fixtures/dashboard-0010.json
@@ -0,0 +1,44 @@
+{
+    "dashboard": {
+        "new-dashboard": {
+            "rows": [
+                {
+                    "collapse": false,
+                    "editable": true,
+                    "height": "250px",
+                    "panels": [
+                        {
+                            "bars": false,
+                            "editable": true,
+                            "error": false,
+                            "fill": 1,
+                            "leftYAxisLabel": "left label",
+                            "lines": true,
+                            "linewidth": 2,
+                            "percentage": false,
+                            "pointradius": 5,
+                            "points": false,
+                            "rightYAxisLabel": "right label",
+                            "span": 12,
+                            "stack": false,
+                            "steppedLine": false,
+                            "targets": [],
+                            "title": "no title (click here)",
+                            "type": "graph",
+                            "x-axis": true,
+                            "y-axis": true,
+                            "y_formats": [
+                                "hertz",
+                                "\u00b5s"
+                            ]
+                        }
+                    ],
+                    "showTitle": false,
+                    "title": "New row"
+                }
+            ],
+            "timezone": "utc",
+            "title": "New dashboard"
+        }
+    }
+}
diff --git a/tests/schema/fixtures/dashboard-0010.yaml b/tests/schema/fixtures/dashboard-0010.yaml
new file mode 100644
index 0000000..4f767d7
--- /dev/null
+++ b/tests/schema/fixtures/dashboard-0010.yaml
@@ -0,0 +1,15 @@
+# -*- coding: utf-8 -*-
+
+dashboard:
+  title: New dashboard
+  rows:
+    - title: New row
+      height: 250px
+      panels:
+          - title: no title (click here)
+            type: graph
+            leftYAxisLabel: left label
+            rightYAxisLabel: right label
+            y_formats:
+              - hertz
+              - µs