diff --git a/include/swift/Basic/BlockListAction.def b/include/swift/Basic/BlockListAction.def
index 11d73387df262..a42886b40af46 100644
--- a/include/swift/Basic/BlockListAction.def
+++ b/include/swift/Basic/BlockListAction.def
@@ -24,5 +24,6 @@ BLOCKLIST_ACTION(ShouldUseTextualModule)
 BLOCKLIST_ACTION(DowngradeInterfaceVerificationFailure)
 BLOCKLIST_ACTION(ShouldUseLayoutStringValueWitnesses)
 BLOCKLIST_ACTION(SkipEmittingFineModuleTrace)
+BLOCKLIST_ACTION(SkipIndexingModule)
 
 #undef BLOCKLIST_ACTION
diff --git a/lib/Index/Index.cpp b/lib/Index/Index.cpp
index 104c59c926e38..29a3fd45b8c12 100644
--- a/lib/Index/Index.cpp
+++ b/lib/Index/Index.cpp
@@ -2155,6 +2155,12 @@ void index::indexSourceFile(SourceFile *SF, IndexDataConsumer &consumer) {
 
 void index::indexModule(ModuleDecl *module, IndexDataConsumer &consumer) {
   assert(module);
+  auto mName = module->getRealName().str();
+  if (module->getASTContext().blockListConfig.hasBlockListAction(mName,
+      BlockListKeyKind::ModuleName,
+      BlockListAction::SkipIndexingModule)) {
+    return;
+  }
   IndexSwiftASTWalker walker(consumer, module->getASTContext());
   walker.visitModule(*module);
   consumer.finish();