[Chilli] Unable to compile with MatrixSSL for SSL redir support

[James]

I'm compiling CoovaChilli 1.3.0 with OpenWRT (buildroot) and all is well 
until when I try to compile coova with --with-matrixssl

I get the following error:

[snip]
checking for matrixSslOpen in -lmatrixssl... no
configure: error: in 
`/home/james/openwrt/openwrt/build_dir/target-mips_34kc_uClibc-0.9.33.2/coova-chilli-1.3.0':
configure: error: --with-matrixssl was given, but test for matrixssl failed
make[4]: *** 
[/home/james/openwrt/openwrt/build_dir/target-mips_34kc_uClibc-0.9.33.2/coova-chilli-1.3.0/.configured_nnnnnn] 
Error 1
make[4]: Leaving directory 
`/home/james/openwrt/openwrt/feeds/packages/net/coova-chilli'
make[3]: *** [package/feeds/packages/coova-chilli/compile] Error 2
make[3]: Leaving directory `/home/james/openwrt/openwrt'
make[2]: *** 
[/home/james/openwrt/openwrt/staging_dir/target-mips_34kc_uClibc-0.9.33.2/stamp/.package_compile] 
Error 2
make[2]: Leaving directory `/home/james/openwrt/openwrt'
make[1]: *** [world] Error 2
make[1]: Leaving directory `/home/james/openwrt/openwrt'
make: *** [firmware] Error 2


I have selected matrixssl and libmatrixssl within the OpenWRT buildroot 
program to ensure that is compiled/enabled.

Might anyone be able to point me in the right direction?

Thanks

James