diff --git a/src/struct_xml/tests/CMakeLists.txt b/src/struct_xml/tests/CMakeLists.txt
index b992d6840..c449ddafb 100644
--- a/src/struct_xml/tests/CMakeLists.txt
+++ b/src/struct_xml/tests/CMakeLists.txt
@@ -1,4 +1,5 @@
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/output/tests)
+add_definitions(-DTHROW_UNKNOWN_KEY)
 add_executable(test_xml
         test_xml.cpp
         test_xml_nothrow.cpp