diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -1,4 +1,7 @@
-INCLUDE_DIRECTORIES(${CMAKE_SOURCE_DIR})
+INCLUDE_DIRECTORIES(
+  ${CMAKE_SOURCE_DIR}
+  ${PROJECT_BINARY_DIR}
+)
 
 LINK_DIRECTORIES(${CMAKE_BINARY_DIR}/lemon)