diff --git a/client/X11/xf_monitor.c b/client/X11/xf_monitor.c
index d13cf0dbd..fb7749421 100644
--- a/client/X11/xf_monitor.c
+++ b/client/X11/xf_monitor.c
@@ -372,6 +372,9 @@ BOOL xf_detect_monitors(xfContext* xfc, UINT32* pMaxWidth, UINT32* pMaxHeight)
 	 * command-line */
 	{
 		int i;
+		UINT32 nr = 0;
+		if (settings->MonitorIds)
+			nr = settings->MonitorIds[0];
 
 		for (i = 0; i < vscreen->nmonitors; i++)
 		{
@@ -414,7 +417,7 @@ BOOL xf_detect_monitors(xfContext* xfc, UINT32* pMaxWidth, UINT32* pMaxHeight)
 
 #endif
 
-			if ((UINT32)i == settings->MonitorIds[0])
+			if ((UINT32)i == nr)
 			{
 				settings->MonitorDefArray[nmonitors].is_primary = TRUE;
 				settings->MonitorLocalShiftX = settings->MonitorDefArray[nmonitors].x;
@@ -512,7 +515,8 @@ BOOL xf_detect_monitors(xfContext* xfc, UINT32* pMaxWidth, UINT32* pMaxHeight)
 			if (settings->NumMonitorIds)
 			{
 				/* The first monitor is the first in the setting which should be used */
-				monitor_index = settings->MonitorIds[0];
+				if (settings->MonitorIds)
+					monitor_index = settings->MonitorIds[0];
 			}
 			else
 			{
diff --git a/libfreerdp/core/settings.c b/libfreerdp/core/settings.c
index 7b28b3308..73e6355b9 100644
--- a/libfreerdp/core/settings.c
+++ b/libfreerdp/core/settings.c
@@ -430,7 +430,7 @@ rdpSettings* freerdp_settings_new(DWORD flags)
 	if (!freerdp_settings_set_uint32(settings, FreeRDP_MonitorLocalShiftY, 0))
 		goto out_fail;
 
-	if (!freerdp_settings_set_pointer_len(settings, FreeRDP_MonitorIds, NULL, 16))
+	if (!freerdp_settings_set_pointer_len(settings, FreeRDP_MonitorIds, NULL, 0))
 		goto out_fail;
 
 	if (!settings_get_computer_name(settings))