diff --git a/src/core/ddsc/CMakeLists.txt b/src/core/ddsc/CMakeLists.txt
index b28a481..b32a4b5 100644
--- a/src/core/ddsc/CMakeLists.txt
+++ b/src/core/ddsc/CMakeLists.txt
@@ -114,7 +114,7 @@ install(
   COMPONENT dev)
 
 # TODO: improve test inclusion.
-if((BUILD_TESTING) AND ((NOT DEFINED MSVC_VERSION) OR (MSVC_VERSION GREATER "1800")))
+if((BUILD_TESTING) AND (BUILD_IDLC) AND ((NOT DEFINED MSVC_VERSION) OR (MSVC_VERSION GREATER "1800")))
   add_subdirectory("${CMAKE_CURRENT_LIST_DIR}/tests")
 endif()