Fortigate 300E IPSEC VPN Default Gateway always one IP above my client IP

Hey everybody.  I have a IPSEC vpn I have setup to a datacenter that hosts a 300E device.  I am able to concect to this VPN tunnel and everything seems to be working great actually.  This VPN tunnel is using the range 10.255.16.10-10.255.16.254 for IP address leases.  My only issue is that once I connect to my tunnel and run an ipconfig on my machine I would expect my default GW to show as 10.255.16.1 as this is what my tunnel interface IP is set as.  Instead of my default gateway is always one IP address above my allocated tunnel IP.  So if the VPN tunnel gives my client 10.255.16.10 then my default gateway on my client will show as 10.255.16.11.  Is this normal?   Is there a way to have my default gateway always be 10.255.16.1?    Thanks in advance.