diff --git a/CMakeLists.txt b/CMakeLists.txt
index bd8887c..fed36b5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -7,13 +7,18 @@ set(CMAKE_PREFIX_PATH
     "C:/dev/boost"
 )
 
-set(LIBRARY_OUTPUT_PATH ${PROJECT_BINARY_DIR}/bin)
-set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/bin)
-
 if (MSVC)
     add_compile_options(/source-charset:utf-8)
 endif()
 
+if(NOT DEFINED LIBRARY_OUTPUT_PATH OR LIBRARY_OUTPUT_PATH STREQUAL "")
+    set(LIBRARY_OUTPUT_PATH ${PROJECT_BINARY_DIR}/bin)
+endif()
+
+if(NOT DEFINED CMAKE_RUNTIME_OUTPUT_DIRECTORY OR CMAKE_RUNTIME_OUTPUT_DIRECTORY STREQUAL "")
+    set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/bin)
+endif()
+
 include_directories(libserial)
 add_subdirectory(libserial)
 add_executable(SerialOprTest main.cpp)