Index: clang-tools-extra/clang-tidy/cppcoreguidelines/MacroUsageCheck.h
===================================================================
--- clang-tools-extra/clang-tidy/cppcoreguidelines/MacroUsageCheck.h
+++ clang-tools-extra/clang-tidy/cppcoreguidelines/MacroUsageCheck.h
@@ -27,7 +27,8 @@
 public:
   MacroUsageCheck(StringRef Name, ClangTidyContext *Context)
       : ClangTidyCheck(Name, Context),
-        AllowedRegexp(Options.get("AllowedRegexp", "^DEBUG_*")),
+        AllowedRegexpStr(Options.get("AllowedRegexp", "^DEBUG_*")),
+        AllowedRegexp(AllowedRegexpStr),
         CheckCapsOnly(Options.get("CheckCapsOnly", false)),
         IgnoreCommandLineMacros(Options.get("IgnoreCommandLineMacros", true)) {}
   bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
@@ -41,7 +42,10 @@
 
 private:
   /// A regular expression that defines how allowed macros must look like.
-  std::string AllowedRegexp;
+  /// Store compiled and original to allow serialisation.
+  std::string AllowedRegexpStr;
+  llvm::Regex AllowedRegexp;
+
   /// Control if only the check shall only test on CAPS_ONLY macros.
   bool CheckCapsOnly;
   /// Should the macros without a valid location be diagnosed?
Index: clang-tools-extra/clang-tidy/cppcoreguidelines/MacroUsageCheck.cpp
===================================================================
--- clang-tools-extra/clang-tidy/cppcoreguidelines/MacroUsageCheck.cpp
+++ clang-tools-extra/clang-tidy/cppcoreguidelines/MacroUsageCheck.cpp
@@ -32,7 +32,7 @@
 class MacroUsageCallbacks : public PPCallbacks {
 public:
   MacroUsageCallbacks(MacroUsageCheck *Check, const SourceManager &SM,
-                      StringRef RegExp, bool CapsOnly, bool IgnoreCommandLine)
+                      const llvm::Regex &RegExp, bool CapsOnly, bool IgnoreCommandLine)
       : Check(Check), SM(SM), RegExp(RegExp), CheckCapsOnly(CapsOnly),
         IgnoreCommandLineMacros(IgnoreCommandLine) {}
   void MacroDefined(const Token &MacroNameTok,
@@ -47,7 +47,7 @@
       return;
 
     StringRef MacroName = MacroNameTok.getIdentifierInfo()->getName();
-    if (!CheckCapsOnly && !llvm::Regex(RegExp).match(MacroName))
+    if (!CheckCapsOnly && !RegExp.match(MacroName))
       Check->warnMacro(MD, MacroName);
 
     if (CheckCapsOnly && !isCapsOnly(MacroName))
@@ -57,14 +57,14 @@
 private:
   MacroUsageCheck *Check;
   const SourceManager &SM;
-  StringRef RegExp;
+  const llvm::Regex &RegExp;
   bool CheckCapsOnly;
   bool IgnoreCommandLineMacros;
 };
 } // namespace
 
 void MacroUsageCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
-  Options.store(Opts, "AllowedRegexp", AllowedRegexp);
+  Options.store(Opts, "AllowedRegexp", AllowedRegexpStr);
   Options.store(Opts, "CheckCapsOnly", CheckCapsOnly);
   Options.store(Opts, "IgnoreCommandLineMacros", IgnoreCommandLineMacros);
 }