diff --git a/FMIAXNetwork.cpp b/FMIAXNetwork.cpp
index 28350a6..9f51bf9 100644
--- a/FMIAXNetwork.cpp
+++ b/FMIAXNetwork.cpp
@@ -525,7 +525,8 @@ bool CFMIAXNetwork::writeNew()
 #if defined(DEBUG_IAX)
 	LogDebug("IAX NEW sent");
 #endif
-	unsigned short sCall = ++m_sCallNo | 0x8000U;
+	m_sCallNo++;
+	unsigned short sCall = m_sCallNo | 0x8000U;
 
 	m_timestamp.start();