libmodsec compilation fail

libtool: compile:  g++ -DHAVE_CONFIG_H -I. -std=c++11 -I.. -g -fPIC -O3 -I ../headers -DWITH_GEOIP -I/usr/include/ -DWITH_YAJL -I/usr/include/yajl -DWITH_LMDB -I/usr/include -DPCRE_HAVE_JIT -I/usr/include/libxml2 -DWITH_LIBXML2 -g -O2 -MT collection/backend/libmodsecurity_la-lmdb.lo -MD -MP -MF collection/backend/.deps/libmodsecurity_la-lmdb.Tpo -c collection/backend/lmdb.cc  -fPIC -DPIC -o collection/backend/.libs/libmodsecurity_la-lmdb.o
collection/backend/lmdb.cc: In member function 'virtual void modsecurity::collection::backend::LMDB::resolveMultiMatches(const string&, std::vector<const modsecurity::collection::Variable*>*)':
collection/backend/lmdb.cc:543:44: error: 'strncmp' was not declared in this scope
         if (strncmp(var.c_str(), a, keySize) != 0) {
                                            ^