Configure the systemd unit anyway, it will then be installed by systemd_dounit
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -728,47 +728,12 @@ if(NOT WIN32)
 
         message(STATUS "  rc.d: YES (${RCD_DIR})")
     elseif(CMAKE_SYSTEM_NAME STREQUAL "Linux")
-        # Linux - check for systemd
-        find_package(PkgConfig QUIET)
-        if(PkgConfig_FOUND)
-            pkg_check_modules(SYSTEMD QUIET systemd)
-        endif()
-
-        if(SYSTEMD_FOUND)
-            # systemd is available - install systemd service
-            # Get systemd unit directory
-            pkg_get_variable(SYSTEMD_UNIT_DIR systemd systemdsystemunitdir)
-            if(NOT SYSTEMD_UNIT_DIR)
-                # Fallback to common location
-                set(SYSTEMD_UNIT_DIR "/lib/systemd/system")
-            endif()
-
             # Configure and install systemd service file
             configure_file(
                 ${CMAKE_CURRENT_SOURCE_DIR}/scripts/3proxy.service.in
                 ${CMAKE_CURRENT_BINARY_DIR}/3proxy.service
                 @ONLY
             )
-            install(FILES ${CMAKE_CURRENT_BINARY_DIR}/3proxy.service
-                DESTINATION ${SYSTEMD_UNIT_DIR}
-            )
-
-            message(STATUS "  systemd: YES (${SYSTEMD_UNIT_DIR})")
-        else()
-            # No systemd - install init.d script
-            configure_file(
-                ${CMAKE_CURRENT_SOURCE_DIR}/scripts/init.d/3proxy.in
-                ${CMAKE_CURRENT_BINARY_DIR}/3proxy.init
-                @ONLY
-            )
-            install(FILES ${CMAKE_CURRENT_BINARY_DIR}/3proxy.init
-                DESTINATION /etc/init.d
-                RENAME 3proxy
-                PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE
-            )
-
-            message(STATUS "  systemd: NO (using init.d)")
-        endif()
     else()
         # Other Unix - install init.d script
         configure_file(