diff --git a/CMakeLists.txt b/CMakeLists.txt
index 09ccc5fa..5912dc1b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -60,9 +60,12 @@ set(D_VERSION               2                                           CACHE ST
 set(PROGRAM_PREFIX          ""                                          CACHE STRING "prepended to ldc binary name")
 set(PROGRAM_SUFFIX          ""                                          CACHE STRING "appended to ldc binary name")
 set(CONF_INST_DIR           ${SYSCONF_INSTALL_DIR}                      CACHE PATH   "Set ldc.conf directory for installation")
+
+# The following flags are currently not well tested, expect the build to fail.
 option(USE_BOEHM_GC "use the Boehm garbage collector internally")
 option(GENERATE_OFFTI "generate complete ClassInfo.offTi arrays")
 option(USE_METADATA "use metadata and related custom optimization passes")
+mark_as_advanced(USE_BOEHM_GC GENERATE_OFFTI USE_METADATA)
 
 if(D_VERSION EQUAL 1)
     set(DMDFE_PATH dmd)