diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -6925,6 +6925,7 @@
 def _SLASH_Bt : CLFlag<"Bt">;
 def _SLASH_Bt_plus : CLFlag<"Bt+">;
 def _SLASH_clr : CLJoined<"clr">;
+def _SLASH_d1 : CLJoined<"d1">;
 def _SLASH_d2 : CLJoined<"d2">;
 def _SLASH_doc : CLJoined<"doc">;
 def _SLASH_experimental : CLJoined<"experimental:">;
diff --git a/clang/test/Driver/cl-options.c b/clang/test/Driver/cl-options.c
--- a/clang/test/Driver/cl-options.c
+++ b/clang/test/Driver/cl-options.c
@@ -426,6 +426,8 @@
 // RUN:     /Bt \
 // RUN:     /Bt+ \
 // RUN:     /clr:pure \
+// RUN:     /d1import_no_registry \
+// RUN:     /d1nodatetime \
 // RUN:     /d2FH4 \
 // RUN:     /docname \
 // RUN:     /experimental:external \