diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 95f13cc38453..396b02fc67f3 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -559,6 +559,7 @@ def filelist : Separate<["-"], "filelist">, Flags<[LinkerInput]>;
 def : Flag<["-"], "findirect-virtual-calls">, Alias<fapple_kext>;
 def finline_functions : Flag<["-"], "finline-functions">, Group<clang_ignored_f_Group>;
 def finline : Flag<["-"], "finline">, Group<clang_ignored_f_Group>;
+def finput_charset_EQ : Joined<["-"], "finput-charset=">, Group<f_Group>;
 def finstrument_functions : Flag<["-"], "finstrument-functions">, Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Generate calls to instrument function entry and exit">;
 def : Flag<["-"], "fkeep-inline-functions">, Group<clang_ignored_f_Group>;
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index c7211686e942..823816791821 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -3911,6 +3911,14 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     D.Diag(diag::err_drv_clang_unsupported)
       << Args.getLastArg(options::OPT_fno_for_scope)->getAsString(Args);
 
+  // -finput_charset=UTF-8 is default. Reject others
+  if (Arg *inputCharset = Args.getLastArg(
+          options::OPT_finput_charset_EQ)) {
+      StringRef value = inputCharset->getValue();
+      if (value != "UTF-8")
+          D.Diag(diag::err_drv_invalid_value) << inputCharset->getAsString(Args) << value;
+  }
+
   // -fcaret-diagnostics is default.
   if (!Args.hasFlag(options::OPT_fcaret_diagnostics,
                     options::OPT_fno_caret_diagnostics, true))
diff --git a/clang/test/Driver/clang_f_opts.c b/clang/test/Driver/clang_f_opts.c
index c88ced05ac35..664ee8a3a4f1 100644
--- a/clang/test/Driver/clang_f_opts.c
+++ b/clang/test/Driver/clang_f_opts.c
@@ -129,6 +129,9 @@
 // RUN: %clang -S -O20 -o /dev/null %s 2>&1 | FileCheck -check-prefix=CHECK-INVALID-O %s
 // CHECK-INVALID-O: warning: optimization level '-O20' is unsupported; using '-O3' instead
 
+// RUN: %clang -### -S -finput-charset=iso-8859-1 -o /dev/null %s 2>&1 | FileCheck -check-prefix=CHECK-INVALID-CHARSET %s
+// CHECK-INVALID-CHARSET: error: invalid value 'iso-8859-1' in '-finput-charset=iso-8859-1'
+
 // Test that we don't error on these.
 // RUN: %clang -### -S -Werror                                                \
 // RUN:     -falign-functions -falign-functions=2 -fno-align-functions        \
@@ -140,6 +143,7 @@
 // RUN:     -fgcse -fno-gcse                                                  \
 // RUN:     -fident -fno-ident                                                \
 // RUN:     -fimplicit-templates -fno-implicit-templates                      \
+// RUN:     -finput-charset=UTF-8                                             \
 // RUN:     -fivopts -fno-ivopts                                              \
 // RUN:     -fnon-call-exceptions -fno-non-call-exceptions                    \
 // RUN:     -fpermissive -fno-permissive                                      \