Index: src/modules/plusgpl/CMakeLists.txt
--- src/modules/plusgpl/CMakeLists.txt.orig
+++ src/modules/plusgpl/CMakeLists.txt
@@ -16,7 +16,7 @@ target_link_libraries(mltplusgpl PRIVATE mlt m Threads
 
 if(WIN32)
   target_link_libraries(mltplusgpl PRIVATE ws2_32)
-elseif(UNIX AND NOT APPLE)
+elseif(UNIX AND NOT APPLE AND NOT ${CMAKE_SYSTEM_NAME} STREQUAL "OpenBSD")
   target_link_libraries(mltplusgpl PRIVATE rt)
 endif()
 
