diff --git a/src/plugins/scripts/python/CMakeLists.txt b/src/plugins/scripts/python/CMakeLists.txt
index 33ff07e..4d6d225 100644
--- a/src/plugins/scripts/python/CMakeLists.txt
+++ b/src/plugins/scripts/python/CMakeLists.txt
@@ -20,6 +20,9 @@ weechat-python-api.c weechat-python-api.h)
 SET_TARGET_PROPERTIES(python PROPERTIES PREFIX "")
 
 IF(PYTHON_FOUND)
+  IF(${CMAKE_SYSTEM_NAME} MATCHES "OpenBSD")
+    ADD_DEFINITIONS(-pthread)
+  ENDIF(${CMAKE_SYSTEM_NAME} MATCHES "OpenBSD")
   INCLUDE_DIRECTORIES(${PYTHON_INCLUDE_PATH})
   SET(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} ${PYTHON_LFLAGS}")
   TARGET_LINK_LIBRARIES(python ${PYTHON_LIBRARY} weechat_scripts)