Index: lib/Format/UnwrappedLineFormatter.cpp
===================================================================
--- lib/Format/UnwrappedLineFormatter.cpp
+++ lib/Format/UnwrappedLineFormatter.cpp
@@ -483,6 +483,12 @@
     if (Line.First->isOneOf(tok::kw_else, tok::kw_case) ||
         (Line.First->Next && Line.First->Next->is(tok::kw_else)))
       return 0;
+    // default: in switch statement
+    if (Line.First->is(tok::kw_default)) {
+      const FormatToken *Tok = Line.First->getNextNonComment();
+      if (Tok && Tok->is(tok::colon))
+        return 0;
+    }
     if (Line.First->isOneOf(tok::kw_if, tok::kw_while, tok::kw_do, tok::kw_try,
                             tok::kw___try, tok::kw_catch, tok::kw___finally,
                             tok::kw_for, tok::r_brace, Keywords.kw___except)) {
Index: unittests/Format/FormatTest.cpp
===================================================================
--- unittests/Format/FormatTest.cpp
+++ unittests/Format/FormatTest.cpp
@@ -999,6 +999,24 @@
                    "  }\n"
                    "});",
                    getLLVMStyle()));
+  EXPECT_EQ("switch (n) {\n"
+            "case 0: {\n"
+            "  return false;\n"
+            "}\n"
+            "default: {\n"
+            "  return true;\n"
+            "}\n"
+            "}",
+            format("switch (n)\n"
+                   "{\n"
+                   "case 0: {\n"
+                   "  return false;\n"
+                   "}\n"
+                   "default: {\n"
+                   "  return true;\n"
+                   "}\n"
+                   "}",
+                   getLLVMStyle()));
   verifyFormat("switch (a) {\n"
                "case (b):\n"
                "  return;\n"