diff --git a/ports/opencv/usage b/ports/opencv/usage
index b9df60b82d5..1c30e5feaf1 100644
--- a/ports/opencv/usage
+++ b/ports/opencv/usage
@@ -1,5 +1,5 @@
 The package opencv provides CMake integration:
 
     find_package(OpenCV REQUIRED)
-    include_directories(${OpenCV_INCLUDE_DIRS})
+    target_include_directories(main PRIVATE ${OpenCV_INCLUDE_DIRS})
     target_link_libraries(main PRIVATE ${OpenCV_LIBS})