diff --git a/clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp b/clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp
index b09079b5e8ba..6c5054fdca28 100644
--- a/clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp
+++ b/clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp
@@ -193,7 +193,8 @@ DiagnosticBuilder ClangTidyContext::diag(const ClangTidyError &Error) {
       SM.getFileManager().getFile(Error.Message.FilePath);
   FileID ID = SM.getOrCreateFileID(*File, SrcMgr::C_User);
   SourceLocation FileStartLoc = SM.getLocForStartOfFile(ID);
-  SourceLocation Loc = FileStartLoc.getLocWithOffset(Error.Message.FileOffset);
+  SourceLocation Loc = FileStartLoc.getLocWithOffset(
+      static_cast<SourceLocation::IntTy>(Error.Message.FileOffset));
   return diag(Error.DiagnosticName, Loc, Error.Message.Message,
               static_cast<DiagnosticIDs::Level>(Error.DiagLevel));
 }