diff --git a/singleapplication_p.cpp b/singleapplication_p.cpp
index 7a98116..f2a95c0 100644
--- a/singleapplication_p.cpp
+++ b/singleapplication_p.cpp
@@ -70,7 +70,7 @@ SingleApplicationPrivate::SingleApplicationPrivate( SingleApplication *q_ptr )
     server = nullptr;
     socket = nullptr;
     memory = nullptr;
-    instanceNumber = -1;
+    instanceNumber = 0;
 }
 
 SingleApplicationPrivate::~SingleApplicationPrivate()