diff --git a/llvm/include/llvm/CGData/CodeGenDataReader.h b/llvm/include/llvm/CGData/CodeGenDataReader.h
index f915ce0afcd7f..a656147a48610 100644
--- a/llvm/include/llvm/CGData/CodeGenDataReader.h
+++ b/llvm/include/llvm/CGData/CodeGenDataReader.h
@@ -16,6 +16,7 @@
 #include "llvm/CGData/CodeGenData.h"
 #include "llvm/CGData/OutlinedHashTreeRecord.h"
 #include "llvm/CGData/StableFunctionMapRecord.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/LineIterator.h"
 #include "llvm/Support/VirtualFileSystem.h"
@@ -99,6 +100,8 @@ class CodeGenDataReader {
   Error success() { return error(cgdata_error::success); }
 };
 
+LLVM_ABI extern cl::opt<bool> IndexedCodeGenDataLazyLoading;
+
 class LLVM_ABI IndexedCodeGenDataReader : public CodeGenDataReader {
   /// The codegen data file contents.
   std::unique_ptr<MemoryBuffer> DataBuffer;