diff --git a/singleapplication_p.cpp b/singleapplication_p.cpp
index 705609f..891f5a0 100644
--- a/singleapplication_p.cpp
+++ b/singleapplication_p.cpp
@@ -187,8 +187,7 @@ void SingleApplicationPrivate::startPrimary()
 
     inst->primary = true;
     inst->primaryPid = q->applicationPid();
-    strncpy( inst->primaryUser, getUsername().toUtf8().data(), 127 );
-    inst->primaryUser[127] = '\0';
+    qstrncpy( inst->primaryUser, getUsername().toUtf8().data(), sizeof(inst->primaryUser) );
     inst->checksum = blockChecksum();
 
     instanceNumber = 0;