diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5b85ee7..178a154 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -47,9 +47,9 @@ INSTALL(TARGETS serial
 
 INSTALL(FILES include/serial.h DESTINATION include)
 
-IF(NOT DEFINED(CMAKE_FIND_INSTALL_PATH))
+IF(NOT CMAKE_FIND_INSTALL_PATH)
     set(CMAKE_FIND_INSTALL_PATH ${CMAKE_ROOT})
-ENDIF(NOT DEFINED(CMAKE_FIND_INSTALL_PATH))
+ENDIF(NOT CMAKE_FIND_INSTALL_PATH)
 
 INSTALL(FILES Findserial.cmake DESTINATION ${CMAKE_FIND_INSTALL_PATH}/Modules/)