diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 1c749e3..5d3ff2a 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -4684,6 +4684,8 @@
 // FIXME: This diagnostic sucks
 def err_literal_operator_params : Error<
   "parameter declaration for literal operator %0 is not valid">;
+def err_literal_operator_extern_c : Error<
+  "literal operator must have C++ linkage">;
 def warn_user_literal_hexfloat : Warning<
   "user-defined literal with suffix '%0' is preempted by C99 hexfloat "
   "extension">, InGroup<UserDefinedLiterals>;
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index 4f0e160..3464880 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -9297,12 +9297,17 @@
     return true;
   }
 
+  if (FnDecl->isExternC()) {
+    Diag(FnDecl->getLocation(), diag::err_literal_operator_extern_c);
+    return true;
+  }
+
   bool Valid = false;
 
   // template <char...> type operator "" name() is the only valid template
   // signature, and the only valid signature with no parameters.
-  if (FnDecl->param_size() == 0) {
-    if (FunctionTemplateDecl *TpDecl = FnDecl->getDescribedFunctionTemplate()) {
+  if (FunctionTemplateDecl *TpDecl = FnDecl->getDescribedFunctionTemplate()) {
+    if (FnDecl->param_size() == 0) {
       // Must have only one template parameter
       TemplateParameterList *Params = TpDecl->getTemplateParameters();
       if (Params->size() == 1) {
@@ -9315,11 +9320,11 @@
           Valid = true;
       }
     }
-  } else {
+  } else if (FnDecl->param_size()) {
     // Check the first parameter
     FunctionDecl::param_iterator Param = FnDecl->param_begin();
 
-    QualType T = (*Param)->getType();
+    QualType T = (*Param)->getType().getUnqualifiedType();
 
     // unsigned long long int, long double, and any character type are allowed
     // as the only parameters.
@@ -9339,7 +9344,7 @@
     if (!PT)
       goto FinishedParams;
     T = PT->getPointeeType();
-    if (!T.isConstQualified())
+    if (!T.isConstQualified() || T.isVolatileQualified())
       goto FinishedParams;
     T = T.getUnqualifiedType();
 
diff --git a/test/CXX/over/over.oper/over.literal/p2.cpp b/test/CXX/over/over.oper/over.literal/p2.cpp
new file mode 100644
index 0000000..fb11ca5
--- /dev/null
+++ b/test/CXX/over/over.oper/over.literal/p2.cpp
@@ -0,0 +1,27 @@
+// RUN: %clang_cc1 -std=c++11 %s -verify
+
+void operator "" _a(const char *);
+
+namespace N {
+  using ::operator "" _a;
+
+  void operator "" _b(const char *);
+}
+
+using N::operator "" _b;
+
+class C {
+  void operator "" _c(const char *); // expected-error {{must be in a namespace or global scope}}
+
+  friend void operator "" _d(const char *);
+};
+
+int operator "" _e; // expected-error {{cannot be the name of a variable}}
+
+void f() {
+  int operator "" _f; // expected-error {{cannot be the name of a variable}}
+}
+
+extern "C++" {
+  void operator "" _g(const char *);
+}
diff --git a/test/CXX/over/over.oper/over.literal/p3.cpp b/test/CXX/over/over.oper/over.literal/p3.cpp
new file mode 100644
index 0000000..0b5323b
--- /dev/null
+++ b/test/CXX/over/over.oper/over.literal/p3.cpp
@@ -0,0 +1,39 @@
+// RUN: %clang_cc1 -std=c++11 %s -verify
+
+using size_t = decltype(sizeof(int));
+
+// Acceptable parameter declarations
+char operator "" _a(const char *);
+char operator "" _a(const char []);
+char operator "" _a(unsigned long long);
+char operator "" _a(long double);
+char operator "" _a(char);
+char operator "" _a(const volatile char);
+char operator "" _a(wchar_t);
+char operator "" _a(char16_t);
+char operator "" _a(char32_t);
+char operator "" _a(const char *, size_t);
+char operator "" _a(const wchar_t *, size_t);
+char operator "" _a(const char16_t *, size_t);
+char operator "" _a(const char32_t *, size_t);
+char operator "" _a(const char [32], size_t);
+
+// Unacceptable parameter declarations
+char operator "" _b(); // expected-error {{parameter}}
+char operator "" _b(const wchar_t *); // expected-error {{parameter}}
+char operator "" _b(long long); // expected-error {{parameter}}
+char operator "" _b(double); // expected-error {{parameter}}
+char operator "" _b(short); // expected-error {{parameter}}
+char operator "" _a(char, int = 0); // expected-error {{parameter}}
+char operator "" _b(unsigned short); // expected-error {{parameter}}
+char operator "" _b(signed char); // expected-error {{parameter}}
+char operator "" _b(unsigned char); // expected-error {{parameter}}
+char operator "" _b(const short *, size_t); // expected-error {{parameter}}
+char operator "" _b(const unsigned short *, size_t); // expected-error {{parameter}}
+char operator "" _b(const signed char *, size_t); // expected-error {{parameter}}
+char operator "" _b(const unsigned char *, size_t); // expected-error {{parameter}}
+char operator "" _a(const volatile char *, size_t); // expected-error {{parameter}}
+char operator "" _a(volatile wchar_t *, size_t); // expected-error {{parameter}}
+char operator "" _a(char16_t *, size_t); // expected-error {{parameter}}
+char operator "" _a(const char32_t *, size_t, bool = false); // expected-error {{parameter}}
+char operator "" _a(const char *, signed long); // expected-error {{parameter}}
diff --git a/test/CXX/over/over.oper/over.literal/p5.cpp b/test/CXX/over/over.oper/over.literal/p5.cpp
new file mode 100644
index 0000000..7a782fc
--- /dev/null
+++ b/test/CXX/over/over.oper/over.literal/p5.cpp
@@ -0,0 +1,18 @@
+// RUN: %clang_cc1 -std=c++11 %s -verify
+
+using size_t = decltype(sizeof(int));
+template<char...> struct S {};
+
+template<char...> void operator "" _a();
+template<char... C> S<C...> operator "" _a();
+
+template<typename T> struct U {
+  // FIXME: It's not entirely clear whether this is intended to be legal.
+  friend U operator "" _a(const T *, size_t); // expected-error {{parameter}}
+};
+
+template<char... C, int N = 0> void operator "" _b(); // expected-error {{parameter}}
+template<char... C> void operator "" _b(int N = 0); // expected-error {{parameter}}
+template<char, char...> void operator "" _b(); // expected-error {{parameter}}
+template<typename T> T operator "" _b(const char *); // expected-error {{parameter}}
+template<typename T> int operator "" _b(const T *, size_t); // expected-error {{parameter}}
diff --git a/test/CXX/over/over.oper/over.literal/p6.cpp b/test/CXX/over/over.oper/over.literal/p6.cpp
new file mode 100644
index 0000000..6bfb856
--- /dev/null
+++ b/test/CXX/over/over.oper/over.literal/p6.cpp
@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 -std=c++11 %s -verify
+
+extern "C" void operator "" _a(const char *); // expected-error {{must have C++ linkage}}
+extern "C" template<char...> void operator "" _b(); // expected-error {{must have C++ linkage}}
+
+extern "C" {
+  void operator "" _c(const char *); // expected-error {{must have C++ linkage}}
+  template<char...> void operator "" _d(); // expected-error {{must have C++ linkage}}
+  namespace N {
+    void operator "" _e(const char *); // expected-error {{must have C++ linkage}}
+    template<char...> void operator "" _f(); // expected-error {{must have C++ linkage}}
+  }
+}
diff --git a/test/CXX/over/over.oper/over.literal/p7.cpp b/test/CXX/over/over.oper/over.literal/p7.cpp
new file mode 100644
index 0000000..72411b9
--- /dev/null
+++ b/test/CXX/over/over.oper/over.literal/p7.cpp
@@ -0,0 +1,16 @@
+// RUN: %clang_cc1 -std=c++11 %s -verify
+
+constexpr int operator "" _a(const char *c) {
+  return c[0];
+}
+
+static_assert(operator "" _a("foo") == 'f', "");
+
+void puts(const char *);
+static inline void operator "" _puts(const char *c) {
+  puts(c);
+}
+void f() {
+  operator "" _puts("foo");
+  operator "" _puts("bar");
+}
diff --git a/test/CXX/over/over.oper/over.literal/p8.cpp b/test/CXX/over/over.oper/over.literal/p8.cpp
new file mode 100644
index 0000000..fe94b53
--- /dev/null
+++ b/test/CXX/over/over.oper/over.literal/p8.cpp
@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -std=c++11 %s -verify
+
+struct string;
+namespace std {
+  using size_t = decltype(sizeof(int));
+}
+
+void operator "" _km(long double); // ok
+string operator "" _i18n(const char*, std::size_t); // ok
+// FIXME: This should be accepted once we support UCNs
+template<char...> int operator "" \u03C0(); // ok, UCN for lowercase pi // expected-error {{expected identifier}}
+// FIXME: This should be rejected once we lex user-defined literal suffices
+float operator ""E(const char *); // expected-warning {{hexfloat}}
+float operator " " B(const char *); // expected-error {{must be '""'}} expected-warning {{hexfloat}}
+string operator "" 5X(const char *, std::size_t); // expected-error {{expected identifier}}
+double operator "" _miles(double); // expected-error {{parameter}}
+template<char...> int operator "" j(const char*); // expected-error {{parameter}}
diff --git a/test/SemaCXX/literal-operators.cpp b/test/SemaCXX/literal-operators.cpp
index 06ef49f..745a433 100644
--- a/test/SemaCXX/literal-operators.cpp
+++ b/test/SemaCXX/literal-operators.cpp
@@ -35,9 +35,9 @@
 void operator "" _good (c*);
 
 // Check extra cv-qualifiers
-void operator "" _cv_good (volatile const char *, const size_t);
+void operator "" _cv_good (volatile const char *, const size_t); // expected-error {{parameter declaration for literal operator 'operator "" _cv_good' is not valid}}
 
-// Template delcaration (not implemented yet)
-// template <char...> void operator "" good ();
+// Template declaration
+template <char...> void operator "" _good ();
 
 // FIXME: Test some invalid decls that might crop up.