diff --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp
index 7075a6fe33f76..ab1f647481d07 100644
--- a/clang/lib/Format/UnwrappedLineParser.cpp
+++ b/clang/lib/Format/UnwrappedLineParser.cpp
@@ -2612,32 +2612,15 @@ void UnwrappedLineParser::parseObjCInterfaceOrImplementation() {
   // @interface can be followed by a lightweight generic
   // specialization list, then either a base class or a category.
   if (FormatTok->Tok.is(tok::less)) {
-    // Unlike protocol lists, generic parameterizations support
-    // nested angles:
-    //
-    // @interface Foo<ValueType : id <NSCopying, NSSecureCoding>> :
-    //     NSObject <NSCopying, NSSecureCoding>
-    //
-    // so we need to count how many open angles we have left.
-    unsigned NumOpenAngles = 1;
-    do {
-      nextToken();
-      // Early exit in case someone forgot a close angle.
-      if (FormatTok->isOneOf(tok::semi, tok::l_brace) ||
-          FormatTok->Tok.isObjCAtKeyword(tok::objc_end))
-        break;
-      if (FormatTok->Tok.is(tok::less))
-        ++NumOpenAngles;
-      else if (FormatTok->Tok.is(tok::greater)) {
-        assert(NumOpenAngles > 0 && "'>' makes NumOpenAngles negative");
-        --NumOpenAngles;
-      }
-    } while (!eof() && NumOpenAngles != 0);
-    nextToken(); // Skip '>'.
+    parseObjCLightweightGenerics();
   }
   if (FormatTok->Tok.is(tok::colon)) {
     nextToken();
     nextToken(); // base class name
+    // The base class can also have lightweight generics applied to it.
+    if (FormatTok->Tok.is(tok::less)) {
+      parseObjCLightweightGenerics();
+    }
   } else if (FormatTok->Tok.is(tok::l_paren))
     // Skip category, if present.
     parseParens();
@@ -2658,6 +2641,32 @@ void UnwrappedLineParser::parseObjCInterfaceOrImplementation() {
   parseObjCUntilAtEnd();
 }
 
+void UnwrappedLineParser::parseObjCLightweightGenerics() {
+  assert(FormatTok->Tok.is(tok::less));
+  // Unlike protocol lists, generic parameterizations support
+  // nested angles:
+  //
+  // @interface Foo<ValueType : id <NSCopying, NSSecureCoding>> :
+  //     NSObject <NSCopying, NSSecureCoding>
+  //
+  // so we need to count how many open angles we have left.
+  unsigned NumOpenAngles = 1;
+  do {
+    nextToken();
+    // Early exit in case someone forgot a close angle.
+    if (FormatTok->isOneOf(tok::semi, tok::l_brace) ||
+        FormatTok->Tok.isObjCAtKeyword(tok::objc_end))
+      break;
+    if (FormatTok->Tok.is(tok::less))
+      ++NumOpenAngles;
+    else if (FormatTok->Tok.is(tok::greater)) {
+      assert(NumOpenAngles > 0 && "'>' makes NumOpenAngles negative");
+      --NumOpenAngles;
+    }
+  } while (!eof() && NumOpenAngles != 0);
+  nextToken(); // Skip '>'.
+}
+
 // Returns true for the declaration/definition form of @protocol,
 // false for the expression form.
 bool UnwrappedLineParser::parseObjCProtocol() {
diff --git a/clang/lib/Format/UnwrappedLineParser.h b/clang/lib/Format/UnwrappedLineParser.h
index 8b3aa4c84edba..d682b4d6acd85 100644
--- a/clang/lib/Format/UnwrappedLineParser.h
+++ b/clang/lib/Format/UnwrappedLineParser.h
@@ -118,6 +118,7 @@ class UnwrappedLineParser {
   // parses the record as a child block, i.e. if the class declaration is an
   // expression.
   void parseRecord(bool ParseAsExpr = false);
+  void parseObjCLightweightGenerics();
   void parseObjCMethod();
   void parseObjCProtocolList();
   void parseObjCUntilAtEnd();
diff --git a/clang/unittests/Format/FormatTestObjC.cpp b/clang/unittests/Format/FormatTestObjC.cpp
index f3be942ab9137..21b8d4701271a 100644
--- a/clang/unittests/Format/FormatTestObjC.cpp
+++ b/clang/unittests/Format/FormatTestObjC.cpp
@@ -328,6 +328,18 @@ TEST_F(FormatTestObjC, FormatObjCInterface) {
                "+ (id)init;\n"
                "@end");
 
+  verifyFormat("@interface Foo<Bar : Baz <Blech>> : Xyzzy <Corge> <Quux> {\n"
+               "  int _i;\n"
+               "}\n"
+               "+ (id)init;\n"
+               "@end");
+
+  verifyFormat("@interface Foo : Bar <Baz> <Blech>\n"
+               "@end");
+
+  verifyFormat("@interface Foo : Bar <Baz> <Blech, Xyzzy, Corge>\n"
+               "@end");
+
   verifyFormat("@interface Foo (HackStuff) {\n"
                "  int _i;\n"
                "}\n"
@@ -413,6 +425,10 @@ TEST_F(FormatTestObjC, FormatObjCInterface) {
                "    fffffffffffff,\n"
                "    fffffffffffff> {\n"
                "}");
+  verifyFormat("@interface ggggggggggggg\n"
+               "    : ggggggggggggg <ggggggggggggg>\n"
+               "      <ggggggggggggg>\n"
+               "@end");
 }
 
 TEST_F(FormatTestObjC, FormatObjCImplementation) {