diff --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp
index 99d5f6279df3398bae816a42a82f3e174f1f4403..131d982906b6f907bdee82222f8d8010c6238d93 100644
--- a/clang/lib/Format/UnwrappedLineParser.cpp
+++ b/clang/lib/Format/UnwrappedLineParser.cpp
@@ -208,6 +208,8 @@ void UnwrappedLineParser::parseStructuralElement() {
     case tok::objc_package:
     case tok::objc_private:
       return parseAccessSpecifier();
+    case tok::objc_interface:
+      return parseObjCInterface();
     default:
       break;
     }
@@ -494,6 +496,46 @@ void UnwrappedLineParser::parseStructOrClass() {
   } while (!eof());
 }
 
+void UnwrappedLineParser::parseObjCInterface() {
+  nextToken();
+  nextToken();  // interface name
+
+  // @interface can be followed by either a base class, or a category.
+  if (FormatTok.Tok.is(tok::colon)) {
+    nextToken();
+    nextToken();  // base class name
+  } else if (FormatTok.Tok.is(tok::l_paren))
+    // Skip category, if present.
+    parseParens();
+
+  // Skip protocol list, if present.
+  if (FormatTok.Tok.is(tok::less)) {
+    do
+      nextToken();
+    while (!eof() && FormatTok.Tok.isNot(tok::greater));
+    nextToken(); // Skip '>'.
+  }
+
+  // If instance variables are present, keep the '{' on the first line too.
+  if (FormatTok.Tok.is(tok::l_brace))
+    parseBlock();
+
+  // With instance variables, this puts '}' on its own line.  Without instance
+  // variables, this ends the @interface line.
+  addUnwrappedLine();
+
+  // Read everything up to the @end.
+  do {
+    if (FormatTok.Tok.isObjCAtKeyword(tok::objc_end)) {
+      nextToken();
+      addUnwrappedLine();
+      break;
+    }
+
+    parseStructuralElement();
+  } while (!eof());
+}
+
 void UnwrappedLineParser::addUnwrappedLine() {
   if (!RootTokenInitialized)
     return;
diff --git a/clang/lib/Format/UnwrappedLineParser.h b/clang/lib/Format/UnwrappedLineParser.h
index 500054fe9a2ede8debfd21b11e0111312ab766de..28ef235190019a19feb31021bc22206bff4be648 100644
--- a/clang/lib/Format/UnwrappedLineParser.h
+++ b/clang/lib/Format/UnwrappedLineParser.h
@@ -142,6 +142,7 @@ private:
   void parseAccessSpecifier();
   void parseEnum();
   void parseStructOrClass();
+  void parseObjCInterface();
   void addUnwrappedLine();
   bool eof() const;
   void nextToken();
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index c21ff24834bbd0f08206f2f4845c995e35a8b2c8..4decf94c766f5dfeaa537883c5958b04e21e8436 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -443,34 +443,6 @@ TEST_F(FormatTest, FormatObjCTryCatch) {
                "}");
 }
 
-TEST_F(FormatTest, FormatObjCInterface) {
-  verifyFormat("@interface Foo : NSObject<NSSomeDelegate> {\n"
-               "@public\n"
-               "  int field1;\n"
-               "@protected\n"
-               "  int field2;\n"
-               "@private\n"
-               "  int field3;\n"
-               "@package\n"
-               "  int field4;\n"
-               "}\n"
-               "+ (id)init;\n"
-               "@end");
-
-  verifyGoogleFormat("@interface Foo : NSObject<NSSomeDelegate> {\n"
-                     " @public\n"
-                     "  int field1;\n"
-                     " @protected\n"
-                     "  int field2;\n"
-                     " @private\n"
-                     "  int field3;\n"
-                     " @package\n"
-                     "  int field4;\n"
-                     "}\n"
-                     "+ (id)init;\n"
-                     "@end");
-}
-
 TEST_F(FormatTest, StaticInitializers) {
   verifyFormat("static SomeClass SC = { 1, 'a' };");
 
@@ -1180,6 +1152,103 @@ TEST_F(FormatTest, FormatObjCBlocks) {
   verifyFormat("int (^Block1) (int, int) = ^(int i, int j)");
 }
 
+TEST_F(FormatTest, FormatObjCInterface) {
+  // FIXME: Handle comments like in "@interface /* wait for it */ Foo", PR14875
+  // FIXME: In google style, it's "+(id) init", not "+ (id)init".
+  verifyFormat("@interface Foo : NSObject<NSSomeDelegate> {\n"
+               "@public\n"
+               "  int field1;\n"
+               "@protected\n"
+               "  int field2;\n"
+               "@private\n"
+               "  int field3;\n"
+               "@package\n"
+               "  int field4;\n"
+               "}\n"
+               "+ (id)init;\n"
+               "@end");
+
+  // FIXME: In LLVM style, there should be a space before '<' for protocols.
+  verifyGoogleFormat("@interface Foo : NSObject<NSSomeDelegate> {\n"
+                     " @public\n"
+                     "  int field1;\n"
+                     " @protected\n"
+                     "  int field2;\n"
+                     " @private\n"
+                     "  int field3;\n"
+                     " @package\n"
+                     "  int field4;\n"
+                     "}\n"
+                     "+ (id)init;\n"
+                     "@end");
+
+  verifyFormat("@interface Foo\n"
+               "+ (id)init;\n"
+               "// Look, a comment!\n"
+               "- (int)answerWith:(int)i;\n"
+               "@end");
+
+  verifyFormat("@interface Foo\n"
+               "@end");
+
+  verifyFormat("@interface Foo : Bar\n"
+               "+ (id)init;\n"
+               "@end");
+
+  verifyFormat("@interface Foo : Bar<Baz, Quux>\n"
+               "+ (id)init;\n"
+               "@end");
+
+  // FIXME: there should be a space before '(' for categories.
+  verifyFormat("@interface Foo(HackStuff)\n"
+               "+ (id)init;\n"
+               "@end");
+
+  verifyFormat("@interface Foo()\n"
+               "+ (id)init;\n"
+               "@end");
+
+  verifyFormat("@interface Foo(HackStuff)<MyProtocol>\n"
+               "+ (id)init;\n"
+               "@end");
+
+  verifyFormat("@interface Foo {\n"
+               "  int _i;\n"
+               "}\n"
+               "+ (id)init;\n"
+               "@end");
+
+  verifyFormat("@interface Foo : Bar {\n"
+               "  int _i;\n"
+               "}\n"
+               "+ (id)init;\n"
+               "@end");
+
+  verifyFormat("@interface Foo : Bar<Baz, Quux> {\n"
+               "  int _i;\n"
+               "}\n"
+               "+ (id)init;\n"
+               "@end");
+
+  verifyFormat("@interface Foo(HackStuff) {\n"
+               "  int _i;\n"
+               "}\n"
+               "+ (id)init;\n"
+               "@end");
+
+  verifyFormat("@interface Foo() {\n"
+               "  int _i;\n"
+               "}\n"
+               "+ (id)init;\n"
+               "@end");
+
+  verifyFormat("@interface Foo(HackStuff)<MyProtocol> {\n"
+               "  int _i;\n"
+               "}\n"
+               "+ (id)init;\n"
+               "@end");
+}
+
 TEST_F(FormatTest, ObjCAt) {
   verifyFormat("@autoreleasepool");
   verifyFormat("@catch");