diff --git a/pppstat.cc b/pppstat.cc
index 71264e4..ca0f11c 100644
--- a/pppstat.cc
+++ b/pppstat.cc
@@ -52,10 +52,10 @@ PPPStat::PPPStat(ToolWindow *toolwindow)
 	lastTimeMil = 0.0;
 	ppp_h = -1;
 #ifndef ISDN
-	active_interface= new char[4];
+	active_interface= new char[5];
 	strcpy(active_interface,"ppp0");
 #else
-	active_interface= new char[5];
+	active_interface= new char[6];
 	strcpy(active_interface,"ippp0");
 #endif
 	connect_status=false;