diff --git a/libs/freetdm/src/isdn/Q931api.c b/libs/freetdm/src/isdn/Q931api.c
index 79f52a4a54..b0119ef68c 100644
--- a/libs/freetdm/src/isdn/Q931api.c
+++ b/libs/freetdm/src/isdn/Q931api.c
@@ -208,9 +208,10 @@ ie Q931AppendIE( L3UCHAR *pm, L3UCHAR *pi)
 
 /*****************************************************************************
 *****************************************************************************/
+static L3INT crv={1};
+
 L3INT Q931GetUniqueCRV(Q931_TrunkInfo_t *pTrunk)
 {
-	static L3INT crv={1};
 	crv++;
 	if (crv > 32766) crv = 1;
 	return crv;