diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 4e2a7b9..a3cea95 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -350,8 +350,23 @@
   Args.AddAllArgs(CmdArgs, options::OPT_clang_W_Group, 
                   options::OPT_pedantic_Group);
   Args.AddLastArg(CmdArgs, options::OPT_w);
-  Args.AddAllArgs(CmdArgs, options::OPT_std_EQ, options::OPT_ansi, 
-                  options::OPT_trigraphs);
+
+  // Handle -{std, ansi, trigraphs} -- take the last of -{std, ansi}
+  // (-ansi is equivalent to -std=c89).
+  //
+  // If a std is supplied, only add -trigraphs if it follows the
+  // option.
+  if (Arg *Std = Args.getLastArg(options::OPT_std_EQ, options::OPT_ansi)) {
+    if (Std->getOption().matches(options::OPT_ansi))
+      CmdArgs.push_back("-std=c89");
+    else
+      Std->render(Args, CmdArgs);
+
+    if (Arg *A = Args.getLastArg(options::OPT_trigraphs))
+      if (A->getIndex() > Std->getIndex())
+        A->render(Args, CmdArgs);
+  } else
+    Args.AddLastArg(CmdArgs, options::OPT_trigraphs);
   
   if (Arg *A = Args.getLastArg(options::OPT_ftemplate_depth_)) {
     CmdArgs.push_back("-ftemplate-depth");
diff --git a/test/Driver/std.c b/test/Driver/std.c
new file mode 100644
index 0000000..ef6d8f1
--- /dev/null
+++ b/test/Driver/std.c
@@ -0,0 +1,8 @@
+// RUN: clang -std=c99 -trigraphs -std=gnu99 %s -E -o %t &&
+// RUN: grep '??(??)' %t &&
+// RUN: clang -ansi %s -E -o %t &&
+// RUN: grep -F '[]' %t &&
+// RUN: clang -std=gnu99 -trigraphs %s -E -o %t &&
+// RUN: grep -F '[]' %t
+
+??(??)
diff --git a/tools/clang-cc/clang-cc.cpp b/tools/clang-cc/clang-cc.cpp
index 9260afe..2843848 100644
--- a/tools/clang-cc/clang-cc.cpp
+++ b/tools/clang-cc/clang-cc.cpp
@@ -585,9 +585,6 @@
 static llvm::cl::opt<bool>
 Trigraphs("trigraphs", llvm::cl::desc("Process trigraph sequences."));
 
-static llvm::cl::opt<bool>
-Ansi("ansi", llvm::cl::desc("Equivalent to specifying -std=c89."));
-
 static llvm::cl::list<std::string>
 TargetFeatures("mattr", llvm::cl::CommaSeparated,
         llvm::cl::desc("Target specific attributes (-mattr=help for details)"));
@@ -653,9 +650,6 @@
     }
   }
   
-  if (Ansi) // "The -ansi option is equivalent to -std=c89."
-    LangStd = lang_c89;
-  
   if (LangStd == lang_unspecified) {
     // Based on the base language, pick one.
     switch (LK) {
@@ -719,8 +713,8 @@
   else
     Options.ImplicitInt = 0;
   
-  // Mimicing gcc's behavior, trigraphs are only enabled if -trigraphs or -ansi
-  // is specified, or -std is set to a conforming mode.  
+  // Mimicing gcc's behavior, trigraphs are only enabled if -trigraphs
+  // is specified, or -std is set to a conforming mode.
   Options.Trigraphs = !Options.GNUMode;
   if (Trigraphs.getPosition())
     Options.Trigraphs = Trigraphs;  // Command line option wins if specified.