--- a/src/configure.ac
+++ b/src/configure.ac
@@ -32,7 +32,19 @@
AC_SYS_LARGEFILE
# OpenBSD needs sys/param.h for mount.h to compile
-AC_CHECK_HEADERS([sys/param.h])
+AC_CHECK_HEADERS([sys/param.h, spawn.h])
+
+AC_CHECK_FUNCS([posix_spawn])
+
+if test "x$ac_cv_func_posix_spawn" = xyes; then :
+ AC_ARG_ENABLE(posix_spawn,
+ AC_HELP_STRING([--enable-posix_spawn],
+ [Enable the use of posix_spawn().]),
+ posixSpawnEnabled=$enableval, posixSpawnEnabled=no)
+fi
+if test X$posixSpawnEnabled = Xyes ; then
+ AC_DEFINE(USE_POSIX_SPAWN, 1, [Use posix_spawn()])
+fi
# Check for where to find unordered_map etc.
AC_LANG_PUSH([C++])