--- /dev/null
+--- CMakeLists.txt.ori
++++ CMakeLists.txt
+@@ -24,6 +24,12 @@ include(CheckIncludeFiles)
+ include_directories("/usr/local/include")
+ link_directories("/usr/local/lib")
+
++
++if (NOT DEFINED CMAKE_INSTALL_SYSCONFDIR )
++ set (CMAKE_INSTALL_SYSCONFDIR ${CMAKE_INSTALL_PREFIX}/etc)
++endif()
++set (SYSCONFDIR ${CMAKE_INSTALL_SYSCONFDIR}/iked)
++
+ if (CMAKE_SYSTEM_NAME MATCHES "Darwin")
+ include_directories("/usr/local/opt/openssl@1.1/include")
+ link_directories("/usr/local/opt/openssl@1.1/lib")
+@@ -32,8 +38,8 @@ elseif(CMAKE_SYSTEM_NAME MATCHES "OpenBSD")
+ add_definitions(-DHAVE_ATTRIBUTE__DEAD__)
+ add_definitions(-DHAVE_SOCKADDR_SA_LEN)
+ elseif(CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
+- add_definitions(-DIKED_CONFIG="/usr/local/etc/iked.conf")
+- add_definitions(-DIKED_CA="/usr/local/etc/iked/")
++ add_definitions(-DIKED_CONFIG="${CMAKE_INSTALL_SYSCONFDIR}/iked.conf")
++ add_definitions(-DIKED_CA="${SYSCONFDIR}")
+ elseif(CMAKE_SYSTEM_NAME MATCHES "Linux")
+ add_definitions(-D_GNU_SOURCE)
+ add_definitions(-D_DEFAULT_SOURCE)