diff --git a/src/mce_display.c b/src/mce_display.c
index 3dd9477..fd6634f 100644
--- a/src/mce_display.c
+++ b/src/mce_display.c
@@ -61,7 +61,7 @@ enum mce_display_signal {
 #define MCE_DISPLAY_OFF_STRING "off"
 #define MCE_DISPLAY_ON_STRING "on"
 
-#define MCE_DISPLAY_SIG "DisplayPowerStateChange"
+#define MCE_DISPLAY_SIG "display-power-state-change"
 
 static guint mce_display_signals[SIGNAL_COUNT] = { 0 };
 
@@ -128,6 +128,7 @@ void
 mce_display_power_state_change(
     ComCanonicalUnityScreen* proxy,
     int32_t status,
+    int32_t reason,
     gpointer arg)
 {
     GDEBUG("Display is %d", status);