diff --git a/include/clang/ASTMatchers/ASTMatchers.h b/include/clang/ASTMatchers/ASTMatchers.h
index 37e82e8..eec1dbf 100644
--- a/include/clang/ASTMatchers/ASTMatchers.h
+++ b/include/clang/ASTMatchers/ASTMatchers.h
@@ -1385,6 +1385,18 @@
   return Matcher.matches(Node.getResultType(), Finder, Builder);
 }
 
+/// \brief Matches extern "C" function declarations.
+///
+/// Given:
+///   extern "C" void f() {}
+///   extern "C" { void g() {} }
+///   void h() {}
+/// function(isExternC())
+///   matches the declaration of f and g, but not the declaration h
+AST_MATCHER(FunctionDecl, isExternC) {
+  return Node.isExternC();
+}
+
 /// \brief Matches the condition expression of an if statement, for loop,
 /// or conditional operator.
 ///
diff --git a/unittests/ASTMatchers/ASTMatchersTest.cpp b/unittests/ASTMatchers/ASTMatchersTest.cpp
index cf37c7d..dba9b7d 100644
--- a/unittests/ASTMatchers/ASTMatchersTest.cpp
+++ b/unittests/ASTMatchers/ASTMatchersTest.cpp
@@ -1099,6 +1099,12 @@
                       function(returns(hasDeclaration(record(hasName("Y")))))));
 }
 
+TEST(IsExternC, MatchesExternCFunctionDeclarations) {
+  EXPECT_TRUE(matches("extern \"C\" void f() {}", function(isExternC())));
+  EXPECT_TRUE(matches("extern \"C\" { void f() {} }", function(isExternC())));
+  EXPECT_TRUE(notMatches("void f() {}", function(isExternC())));
+}
+
 TEST(HasAnyParameter, DoesntMatchIfInnerMatcherDoesntMatch) {
   EXPECT_TRUE(notMatches("class Y {}; class X { void x(int) {} };",
       method(hasAnyParameter(hasType(record(hasName("X")))))));