diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 55f1bc1..0b27e10 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -20,6 +20,8 @@ add_executable(
         ${src_sources}
 )
 target_link_libraries(unit_tests PRIVATE GTest::gtest_main)
+# see src/CMakeLists.txt
+target_compile_definitions(unit_tests PRIVATE OSI_TRACE_FILE_SPEC_VERSION="3.7.1")
 
 # Link against OSI made available by parent CMakeLists.txt
 if (LINK_WITH_SHARED_OSI)