diff --git a/clang-tools-extra/clang-tidy/readability/InconsistentDeclarationParameterNameCheck.cpp b/clang-tools-extra/clang-tidy/readability/InconsistentDeclarationParameterNameCheck.cpp
--- a/clang-tools-extra/clang-tidy/readability/InconsistentDeclarationParameterNameCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/InconsistentDeclarationParameterNameCheck.cpp
@@ -91,8 +91,8 @@
     return L.empty() || R.empty() || L == R;
   // We allow two names if one is a prefix/suffix of the other, ignoring case.
   // Important special case: this is true if either parameter has no name!
-  return L.startswith_insensitive(R) || R.startswith_insensitive(L) ||
-         L.endswith_insensitive(R) || R.endswith_insensitive(L);
+  return L.starts_with_insensitive(R) || R.starts_with_insensitive(L) ||
+         L.ends_with_insensitive(R) || R.ends_with_insensitive(L);
 }
 
 DifferingParamsContainer
diff --git a/clang-tools-extra/clang-tidy/readability/SuspiciousCallArgumentCheck.cpp b/clang-tools-extra/clang-tidy/readability/SuspiciousCallArgumentCheck.cpp
--- a/clang-tools-extra/clang-tidy/readability/SuspiciousCallArgumentCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/SuspiciousCallArgumentCheck.cpp
@@ -154,7 +154,7 @@
   StringRef Shorter = Arg.size() < Param.size() ? Arg : Param;
   StringRef Longer = Arg.size() >= Param.size() ? Arg : Param;
 
-  if (Longer.startswith_insensitive(Shorter))
+  if (Longer.starts_with_insensitive(Shorter))
     return percentage(Shorter.size(), Longer.size()) > Threshold;
 
   return false;
@@ -166,7 +166,7 @@
   StringRef Shorter = Arg.size() < Param.size() ? Arg : Param;
   StringRef Longer = Arg.size() >= Param.size() ? Arg : Param;
 
-  if (Longer.endswith_insensitive(Shorter))
+  if (Longer.ends_with_insensitive(Shorter))
     return percentage(Shorter.size(), Longer.size()) > Threshold;
 
   return false;
diff --git a/clang-tools-extra/clangd/CodeComplete.cpp b/clang-tools-extra/clangd/CodeComplete.cpp
--- a/clang-tools-extra/clangd/CodeComplete.cpp
+++ b/clang-tools-extra/clangd/CodeComplete.cpp
@@ -1884,7 +1884,7 @@
           C.SemaResult->Kind == CodeCompletionResult::RK_Macro) ||
          (C.IndexResult &&
           C.IndexResult->SymInfo.Kind == index::SymbolKind::Macro)) &&
-        !C.Name.startswith_insensitive(Filter->pattern()))
+        !C.Name.starts_with_insensitive(Filter->pattern()))
       return std::nullopt;
     return Filter->match(C.Name);
   }
diff --git a/clang-tools-extra/clangd/CompileCommands.cpp b/clang-tools-extra/clangd/CompileCommands.cpp
--- a/clang-tools-extra/clangd/CompileCommands.cpp
+++ b/clang-tools-extra/clangd/CompileCommands.cpp
@@ -422,9 +422,9 @@
 DriverMode getDriverMode(const std::vector<std::string> &Args) {
   DriverMode Mode = DM_GCC;
   llvm::StringRef Argv0 = Args.front();
-  if (Argv0.endswith_insensitive(".exe"))
+  if (Argv0.ends_with_insensitive(".exe"))
     Argv0 = Argv0.drop_back(strlen(".exe"));
-  if (Argv0.endswith_insensitive("cl"))
+  if (Argv0.ends_with_insensitive("cl"))
     Mode = DM_CL;
   for (const llvm::StringRef Arg : Args) {
     if (Arg == "--driver-mode=cl") {
diff --git a/clang-tools-extra/clangd/InlayHints.cpp b/clang-tools-extra/clangd/InlayHints.cpp
--- a/clang-tools-extra/clangd/InlayHints.cpp
+++ b/clang-tools-extra/clangd/InlayHints.cpp
@@ -430,7 +430,7 @@
       return false;
 
     StringRef Name = getSimpleName(*Callee);
-    if (!Name.startswith_insensitive("set"))
+    if (!Name.starts_with_insensitive("set"))
       return false;
 
     // In addition to checking that the function has one parameter and its
diff --git a/clang/lib/Analysis/RetainSummaryManager.cpp b/clang/lib/Analysis/RetainSummaryManager.cpp
--- a/clang/lib/Analysis/RetainSummaryManager.cpp
+++ b/clang/lib/Analysis/RetainSummaryManager.cpp
@@ -190,18 +190,18 @@
 }
 
 static bool isRetain(const FunctionDecl *FD, StringRef FName) {
-  return FName.startswith_insensitive("retain") ||
-         FName.endswith_insensitive("retain");
+  return FName.starts_with_insensitive("retain") ||
+         FName.ends_with_insensitive("retain");
 }
 
 static bool isRelease(const FunctionDecl *FD, StringRef FName) {
-  return FName.startswith_insensitive("release") ||
-         FName.endswith_insensitive("release");
+  return FName.starts_with_insensitive("release") ||
+         FName.ends_with_insensitive("release");
 }
 
 static bool isAutorelease(const FunctionDecl *FD, StringRef FName) {
-  return FName.startswith_insensitive("autorelease") ||
-         FName.endswith_insensitive("autorelease");
+  return FName.starts_with_insensitive("autorelease") ||
+         FName.ends_with_insensitive("autorelease");
 }
 
 static bool isMakeCollectable(StringRef FName) {
diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -2670,7 +2670,7 @@
   bool Quote = Lib.contains(' ');
   std::string ArgStr = Quote ? "\"" : "";
   ArgStr += Lib;
-  if (!Lib.endswith_insensitive(".lib") && !Lib.endswith_insensitive(".a"))
+  if (!Lib.ends_with_insensitive(".lib") && !Lib.ends_with_insensitive(".a"))
     ArgStr += ".lib";
   ArgStr += Quote ? "\"" : "";
   return ArgStr;
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -693,9 +693,9 @@
     if (Args.hasArg(options::OPT_march_EQ) ||
         Args.hasArg(options::OPT_mcpu_EQ)) {
       StringRef ArchName = tools::riscv::getRISCVArch(Args, Target);
-      if (ArchName.startswith_insensitive("rv32"))
+      if (ArchName.starts_with_insensitive("rv32"))
         Target.setArch(llvm::Triple::riscv32);
-      else if (ArchName.startswith_insensitive("rv64"))
+      else if (ArchName.starts_with_insensitive("rv64"))
         Target.setArch(llvm::Triple::riscv64);
     }
   }
@@ -6166,7 +6166,7 @@
       case llvm::Triple::MSVC:
       case llvm::Triple::UnknownEnvironment:
         if (Args.getLastArgValue(options::OPT_fuse_ld_EQ)
-                .startswith_insensitive("bfd"))
+                .starts_with_insensitive("bfd"))
           TC = std::make_unique<toolchains::CrossWindowsToolChain>(
               *this, Target, Args);
         else
diff --git a/clang/lib/Driver/OffloadBundler.cpp b/clang/lib/Driver/OffloadBundler.cpp
--- a/clang/lib/Driver/OffloadBundler.cpp
+++ b/clang/lib/Driver/OffloadBundler.cpp
@@ -106,11 +106,11 @@
   if (OffloadKind == TargetOffloadKind)
     return true;
   if (BundlerConfig.HipOpenmpCompatible) {
-    bool HIPCompatibleWithOpenMP = OffloadKind.startswith_insensitive("hip") &&
+    bool HIPCompatibleWithOpenMP = OffloadKind.starts_with_insensitive("hip") &&
                                    TargetOffloadKind == "openmp";
     bool OpenMPCompatibleWithHIP =
         OffloadKind == "openmp" &&
-        TargetOffloadKind.startswith_insensitive("hip");
+        TargetOffloadKind.starts_with_insensitive("hip");
     return HIPCompatibleWithOpenMP || OpenMPCompatibleWithHIP;
   }
   return false;
diff --git a/clang/lib/Driver/ToolChains/Arch/RISCV.cpp b/clang/lib/Driver/ToolChains/Arch/RISCV.cpp
--- a/clang/lib/Driver/ToolChains/Arch/RISCV.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/RISCV.cpp
@@ -290,9 +290,9 @@
 
     if (MABI.equals_insensitive("ilp32e"))
       return "rv32e";
-    else if (MABI.startswith_insensitive("ilp32"))
+    else if (MABI.starts_with_insensitive("ilp32"))
       return "rv32imafdc";
-    else if (MABI.startswith_insensitive("lp64"))
+    else if (MABI.starts_with_insensitive("lp64"))
       return "rv64imafdc";
   }
 
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -8252,7 +8252,7 @@
       // Extract GPUArch from -march argument in TC argument list.
       for (unsigned ArgIndex = 0; ArgIndex < TCArgs.size(); ArgIndex++) {
         auto ArchStr = StringRef(TCArgs.getArgString(ArgIndex));
-        auto Arch = ArchStr.startswith_insensitive("-march=");
+        auto Arch = ArchStr.starts_with_insensitive("-march=");
         if (Arch) {
           GPUArchName = ArchStr.substr(7);
           Triples += "-";
@@ -8345,7 +8345,7 @@
       // Extract GPUArch from -march argument in TC argument list.
       for (unsigned ArgIndex = 0; ArgIndex < TCArgs.size(); ArgIndex++) {
         StringRef ArchStr = StringRef(TCArgs.getArgString(ArgIndex));
-        auto Arch = ArchStr.startswith_insensitive("-march=");
+        auto Arch = ArchStr.starts_with_insensitive("-march=");
         if (Arch) {
           GPUArchName = ArchStr.substr(7);
           Triples += "-";
diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -3680,33 +3680,33 @@
 static FormatStyle::LanguageKind getLanguageByFileName(StringRef FileName) {
   if (FileName.endswith(".java"))
     return FormatStyle::LK_Java;
-  if (FileName.endswith_insensitive(".js") ||
-      FileName.endswith_insensitive(".mjs") ||
-      FileName.endswith_insensitive(".ts")) {
+  if (FileName.ends_with_insensitive(".js") ||
+      FileName.ends_with_insensitive(".mjs") ||
+      FileName.ends_with_insensitive(".ts")) {
     return FormatStyle::LK_JavaScript; // (module) JavaScript or TypeScript.
   }
   if (FileName.endswith(".m") || FileName.endswith(".mm"))
     return FormatStyle::LK_ObjC;
-  if (FileName.endswith_insensitive(".proto") ||
-      FileName.endswith_insensitive(".protodevel")) {
+  if (FileName.ends_with_insensitive(".proto") ||
+      FileName.ends_with_insensitive(".protodevel")) {
     return FormatStyle::LK_Proto;
   }
-  if (FileName.endswith_insensitive(".textpb") ||
-      FileName.endswith_insensitive(".pb.txt") ||
-      FileName.endswith_insensitive(".textproto") ||
-      FileName.endswith_insensitive(".asciipb")) {
+  if (FileName.ends_with_insensitive(".textpb") ||
+      FileName.ends_with_insensitive(".pb.txt") ||
+      FileName.ends_with_insensitive(".textproto") ||
+      FileName.ends_with_insensitive(".asciipb")) {
     return FormatStyle::LK_TextProto;
   }
-  if (FileName.endswith_insensitive(".td"))
+  if (FileName.ends_with_insensitive(".td"))
     return FormatStyle::LK_TableGen;
-  if (FileName.endswith_insensitive(".cs"))
+  if (FileName.ends_with_insensitive(".cs"))
     return FormatStyle::LK_CSharp;
-  if (FileName.endswith_insensitive(".json"))
+  if (FileName.ends_with_insensitive(".json"))
     return FormatStyle::LK_Json;
-  if (FileName.endswith_insensitive(".sv") ||
-      FileName.endswith_insensitive(".svh") ||
-      FileName.endswith_insensitive(".v") ||
-      FileName.endswith_insensitive(".vh")) {
+  if (FileName.ends_with_insensitive(".sv") ||
+      FileName.ends_with_insensitive(".svh") ||
+      FileName.ends_with_insensitive(".v") ||
+      FileName.ends_with_insensitive(".vh")) {
     return FormatStyle::LK_Verilog;
   }
   return FormatStyle::LK_Cpp;
@@ -3780,7 +3780,7 @@
 
   // User provided clang-format file using -style=file:path/to/format/file.
   if (!Style.InheritsParentConfig &&
-      StyleName.startswith_insensitive("file:")) {
+      StyleName.starts_with_insensitive("file:")) {
     auto ConfigFile = StyleName.substr(5);
     llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> Text =
         loadAndParseConfigFile(ConfigFile, FS, &Style, AllowUnknownOptions);
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -8490,18 +8490,18 @@
 
     bool ValidString = true;
     if (IsARMBuiltin) {
-      ValidString &= Fields[0].startswith_insensitive("cp") ||
-                     Fields[0].startswith_insensitive("p");
+      ValidString &= Fields[0].starts_with_insensitive("cp") ||
+                     Fields[0].starts_with_insensitive("p");
       if (ValidString)
         Fields[0] = Fields[0].drop_front(
-            Fields[0].startswith_insensitive("cp") ? 2 : 1);
+            Fields[0].starts_with_insensitive("cp") ? 2 : 1);
 
-      ValidString &= Fields[2].startswith_insensitive("c");
+      ValidString &= Fields[2].starts_with_insensitive("c");
       if (ValidString)
         Fields[2] = Fields[2].drop_front(1);
 
       if (FiveFields) {
-        ValidString &= Fields[3].startswith_insensitive("c");
+        ValidString &= Fields[3].starts_with_insensitive("c");
         if (ValidString)
           Fields[3] = Fields[3].drop_front(1);
       }
diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -10030,11 +10030,11 @@
         break;
       case llvm::sys::fs::file_type::regular_file: {
         // Only files that really look like headers. (Except in special dirs).
-        const bool IsHeader = Filename.endswith_insensitive(".h") ||
-                              Filename.endswith_insensitive(".hh") ||
-                              Filename.endswith_insensitive(".hpp") ||
-                              Filename.endswith_insensitive(".hxx") ||
-                              Filename.endswith_insensitive(".inc") ||
+        const bool IsHeader = Filename.ends_with_insensitive(".h") ||
+                              Filename.ends_with_insensitive(".hh") ||
+                              Filename.ends_with_insensitive(".hpp") ||
+                              Filename.ends_with_insensitive(".hxx") ||
+                              Filename.ends_with_insensitive(".inc") ||
                               (ExtensionlessHeaders && !Filename.contains('.'));
         if (!IsHeader)
           break;
diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -7262,7 +7262,7 @@
     return Call;
 
   if (LangOpts.OpenMP >= 51 && CalleeFnDecl->getIdentifier() &&
-      CalleeFnDecl->getName().startswith_insensitive("omp_")) {
+      CalleeFnDecl->getName().starts_with_insensitive("omp_")) {
     // checking for any calls inside an Order region
     if (Scope && Scope->isOpenMPOrderClauseScope())
       Diag(LParenLoc, diag::err_omp_unexpected_call_to_omp_runtime_api);
diff --git a/clang/lib/StaticAnalyzer/Checkers/ContainerModeling.cpp b/clang/lib/StaticAnalyzer/Checkers/ContainerModeling.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/ContainerModeling.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/ContainerModeling.cpp
@@ -749,14 +749,14 @@
   const auto *IdInfo = Func->getIdentifier();
   if (!IdInfo)
     return false;
-  return IdInfo->getName().endswith_insensitive("begin");
+  return IdInfo->getName().ends_with_insensitive("begin");
 }
 
 bool isEndCall(const FunctionDecl *Func) {
   const auto *IdInfo = Func->getIdentifier();
   if (!IdInfo)
     return false;
-  return IdInfo->getName().endswith_insensitive("end");
+  return IdInfo->getName().ends_with_insensitive("end");
 }
 
 const CXXRecordDecl *getCXXRecordDecl(ProgramStateRef State,
diff --git a/clang/lib/StaticAnalyzer/Checkers/Iterator.cpp b/clang/lib/StaticAnalyzer/Checkers/Iterator.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/Iterator.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/Iterator.cpp
@@ -29,8 +29,8 @@
     return false;
 
   const auto Name = CRD->getName();
-  if (!(Name.endswith_insensitive("iterator") ||
-        Name.endswith_insensitive("iter") || Name.endswith_insensitive("it")))
+  if (!(Name.ends_with_insensitive("iterator") ||
+        Name.ends_with_insensitive("iter") || Name.ends_with_insensitive("it")))
     return false;
 
   bool HasCopyCtor = false, HasCopyAssign = true, HasDtor = false,
diff --git a/clang/lib/Tooling/Inclusions/HeaderIncludes.cpp b/clang/lib/Tooling/Inclusions/HeaderIncludes.cpp
--- a/clang/lib/Tooling/Inclusions/HeaderIncludes.cpp
+++ b/clang/lib/Tooling/Inclusions/HeaderIncludes.cpp
@@ -253,7 +253,7 @@
   //  1) foo.h => bar.cc
   //  2) foo.proto.h => foo.cc
   StringRef Matching;
-  if (MatchingFileStem.startswith_insensitive(HeaderStem))
+  if (MatchingFileStem.starts_with_insensitive(HeaderStem))
     Matching = MatchingFileStem; // example 1), 2)
   else if (FileStem.equals_insensitive(HeaderStem))
     Matching = FileStem; // example 3)
diff --git a/lld/COFF/Driver.cpp b/lld/COFF/Driver.cpp
--- a/lld/COFF/Driver.cpp
+++ b/lld/COFF/Driver.cpp
@@ -230,7 +230,7 @@
       ctx.symtab.addFile(make<DLLFile>(ctx, mbref));
       break;
     }
-    if (filename.endswith_insensitive(".dll")) {
+    if (filename.ends_with_insensitive(".dll")) {
       error(filename + ": bad file type. Did you specify a DLL instead of an "
                        "import library?");
       break;
@@ -503,7 +503,7 @@
       return std::nullopt;
   }
 
-  if (path.endswith_insensitive(".lib"))
+  if (path.ends_with_insensitive(".lib"))
     visitedLibs.insert(std::string(sys::path::filename(path).lower()));
   return path;
 }
diff --git a/lld/COFF/DriverUtils.cpp b/lld/COFF/DriverUtils.cpp
--- a/lld/COFF/DriverUtils.cpp
+++ b/lld/COFF/DriverUtils.cpp
@@ -270,13 +270,13 @@
     ctx.config.manifest = Configuration::No;
     return;
   }
-  if (!arg.startswith_insensitive("embed"))
+  if (!arg.starts_with_insensitive("embed"))
     fatal("invalid option " + arg);
   ctx.config.manifest = Configuration::Embed;
   arg = arg.substr(strlen("embed"));
   if (arg.empty())
     return;
-  if (!arg.startswith_insensitive(",id="))
+  if (!arg.starts_with_insensitive(",id="))
     fatal("invalid option " + arg);
   arg = arg.substr(strlen(",id="));
   if (arg.getAsInteger(0, ctx.config.manifestID))
@@ -294,12 +294,12 @@
     arg = arg.ltrim();
     if (arg.empty())
       return;
-    if (arg.startswith_insensitive("level=")) {
+    if (arg.starts_with_insensitive("level=")) {
       arg = arg.substr(strlen("level="));
       std::tie(ctx.config.manifestLevel, arg) = arg.split(" ");
       continue;
     }
-    if (arg.startswith_insensitive("uiaccess=")) {
+    if (arg.starts_with_insensitive("uiaccess=")) {
       arg = arg.substr(strlen("uiaccess="));
       std::tie(ctx.config.manifestUIAccess, arg) = arg.split(" ");
       continue;
@@ -904,14 +904,14 @@
   SmallVector<StringRef, 16> tokens;
   cl::TokenizeWindowsCommandLineNoCopy(s, saver(), tokens);
   for (StringRef tok : tokens) {
-    if (tok.startswith_insensitive("/export:") ||
-        tok.startswith_insensitive("-export:"))
+    if (tok.starts_with_insensitive("/export:") ||
+        tok.starts_with_insensitive("-export:"))
       result.exports.push_back(tok.substr(strlen("/export:")));
-    else if (tok.startswith_insensitive("/include:") ||
-             tok.startswith_insensitive("-include:"))
+    else if (tok.starts_with_insensitive("/include:") ||
+             tok.starts_with_insensitive("-include:"))
       result.includes.push_back(tok.substr(strlen("/include:")));
-    else if (tok.startswith_insensitive("/exclude-symbols:") ||
-             tok.startswith_insensitive("-exclude-symbols:"))
+    else if (tok.starts_with_insensitive("/exclude-symbols:") ||
+             tok.starts_with_insensitive("-exclude-symbols:"))
       result.excludes.push_back(tok.substr(strlen("/exclude-symbols:")));
     else {
       // Copy substrings that are not valid C strings. The tokenizer may have
diff --git a/lld/Common/Args.cpp b/lld/Common/Args.cpp
--- a/lld/Common/Args.cpp
+++ b/lld/Common/Args.cpp
@@ -87,7 +87,7 @@
 }
 
 StringRef lld::args::getFilenameWithoutExe(StringRef path) {
-  if (path.endswith_insensitive(".exe"))
+  if (path.ends_with_insensitive(".exe"))
     return sys::path::stem(path);
   return sys::path::filename(path);
 }
diff --git a/lld/ELF/ScriptParser.cpp b/lld/ELF/ScriptParser.cpp
--- a/lld/ELF/ScriptParser.cpp
+++ b/lld/ELF/ScriptParser.cpp
@@ -1227,24 +1227,24 @@
 static std::optional<uint64_t> parseInt(StringRef tok) {
   // Hexadecimal
   uint64_t val;
-  if (tok.startswith_insensitive("0x")) {
+  if (tok.starts_with_insensitive("0x")) {
     if (!to_integer(tok.substr(2), val, 16))
       return std::nullopt;
     return val;
   }
-  if (tok.endswith_insensitive("H")) {
+  if (tok.ends_with_insensitive("H")) {
     if (!to_integer(tok.drop_back(), val, 16))
       return std::nullopt;
     return val;
   }
 
   // Decimal
-  if (tok.endswith_insensitive("K")) {
+  if (tok.ends_with_insensitive("K")) {
     if (!to_integer(tok.drop_back(), val, 10))
       return std::nullopt;
     return val * 1024;
   }
-  if (tok.endswith_insensitive("M")) {
+  if (tok.ends_with_insensitive("M")) {
     if (!to_integer(tok.drop_back(), val, 10))
       return std::nullopt;
     return val * 1024 * 1024;
diff --git a/lld/MinGW/Driver.cpp b/lld/MinGW/Driver.cpp
--- a/lld/MinGW/Driver.cpp
+++ b/lld/MinGW/Driver.cpp
@@ -437,7 +437,7 @@
   for (auto *a : args) {
     switch (a->getOption().getID()) {
     case OPT_INPUT:
-      if (StringRef(a->getValue()).endswith_insensitive(".def"))
+      if (StringRef(a->getValue()).ends_with_insensitive(".def"))
         add("-def:" + StringRef(a->getValue()));
       else
         add(prefix + StringRef(a->getValue()));
diff --git a/lld/tools/lld/lld.cpp b/lld/tools/lld/lld.cpp
--- a/lld/tools/lld/lld.cpp
+++ b/lld/tools/lld/lld.cpp
@@ -136,7 +136,7 @@
 
   // Deduct the flavor from argv[0].
   StringRef arg0 = path::filename(v[0]);
-  if (arg0.endswith_insensitive(".exe"))
+  if (arg0.ends_with_insensitive(".exe"))
     arg0 = arg0.drop_back(4);
   return parseProgname(arg0);
 }