diff --git a/Device/CMakeLists.txt b/Device/CMakeLists.txt
index f68d827ab9ec866c0b70f0ec8f2f49ce9f98f66f..40a89034bfb97940e3023e2537429cbbf5bdb1d6 100644
--- a/Device/CMakeLists.txt
+++ b/Device/CMakeLists.txt
@@ -35,7 +35,7 @@ target_link_libraries(${lib}
     )
 
 if(WIN32)
-    target_compile_definitions(${lib} -DBA_DEVICE_BUILD_DLL)
+    target_compile_definitions(${lib} PRIVATE -DBA_DEVICE_BUILD_DLL)
 endif()
 if(BORNAGAIN_TIFF_SUPPORT)
     target_compile_definitions(${lib} PUBLIC -DBORNAGAIN_TIFF_SUPPORT)