I'm trying to build the master code base on ubuntu 11.10 to verify a bug I'm seeing on v1.2.stable. I've installed openssl 1.0.1f using the following: wget http://www.openssl.org/source/openssl-1.0.1f.tar.gz tar -zxvf openssl-1.0.1f.tar.gz cd openssl-1.0.1f ./config --prefix=/usr/openssl101f -fPIC make make install The build goes through successfully and the files are in /user/openssl101f. I then check out freeswitch from git: git clone git://git.freeswitch.org/freeswitch.git And then run bootstrap and configure: cd freeswitch ./bootstrap.sh -j ./configure CFLAGS="-I/usr/openssl101f/include" LDFLAGS="-L/usr/openssl101f/lib" At the end of configure I get: checking for tgetent in -ltinfo... yes checking for openssl... yes checking openssl_CFLAGS... checking openssl_LIBS... -lssl -lcrypto adding "-DHAVE_OPENSSL" to SWITCH_AM_CFLAGS checking for SSL_CTX_set_tlsext_use_srtp in -lssl... yes checking for DTLSv1_method in -lssl... no configure: error: OpenSSL >= 1.0.1e and associaed developement headers required I'm not sure why freeswitch isnt picking up on my latest openssl build.