diff --git a/obmc/sensors.py b/obmc/sensors.py
index e923859..fcb3ee6 100644
--- a/obmc/sensors.py
+++ b/obmc/sensors.py
@@ -111,7 +111,10 @@
         if self.Get(iface, 'threshold_state') != current_state and \
                 current_state == "CRITICAL" and \
                 self.Get(iface, 'emergency_enabled') is True:
-            self.Emergency()
+            message = type(self).__name__ + \
+                ' SensorThresholds.check_thresholds(): trigger emergency' + \
+                ' signal, sensor value: ' + str(value)
+            self.Emergency(message)
 
         self.Set(iface, 'threshold_state', current_state)
         worst = self.properties[iface]['worst_threshold_state']
@@ -121,8 +124,8 @@
 
         return rtn
 
-    @dbus.service.signal(IFACE_NAME, signature='')
-    def Emergency(self):
+    @dbus.service.signal(IFACE_NAME, signature='s')
+    def Emergency(self, message):
         pass