diff --git a/lib/Format/BreakableToken.cpp b/lib/Format/BreakableToken.cpp
index c84d9afdd4e8ee5d1736163d89009b7ee9fc9318..66e935abdf558d6e7feda8a750ccf4fdd3be7bc4 100644
--- a/lib/Format/BreakableToken.cpp
+++ b/lib/Format/BreakableToken.cpp
@@ -277,6 +277,8 @@ BreakableBlockComment::BreakableBlockComment(
     // If the last line is empty, the closing "*/" will have a star.
     if (i + 1 == e && Lines[i].empty())
       break;
+    if (!Lines[i].empty() && i + 1 != e && Decoration.startswith(Lines[i]))
+      continue;
     while (!Lines[i].startswith(Decoration))
       Decoration = Decoration.substr(0, Decoration.size() - 1);
   }
@@ -297,14 +299,18 @@ BreakableBlockComment::BreakableBlockComment(
       }
       continue;
     }
+
     // The first line already excludes the star.
     // For all other lines, adjust the line to exclude the star and
     // (optionally) the first whitespace.
-    StartOfLineColumn[i] += Decoration.size();
-    Lines[i] = Lines[i].substr(Decoration.size());
-    LeadingWhitespace[i] += Decoration.size();
-    IndentAtLineBreak =
-        std::min<int>(IndentAtLineBreak, std::max(0, StartOfLineColumn[i]));
+    unsigned DecorationSize =
+        Decoration.startswith(Lines[i]) ? Lines[i].size() : Decoration.size();
+    StartOfLineColumn[i] += DecorationSize;
+    Lines[i] = Lines[i].substr(DecorationSize);
+    LeadingWhitespace[i] += DecorationSize;
+    if (!Decoration.startswith(Lines[i]))
+      IndentAtLineBreak =
+          std::min<int>(IndentAtLineBreak, std::max(0, StartOfLineColumn[i]));
   }
   IndentAtLineBreak = std::max<unsigned>(IndentAtLineBreak, Decoration.size());
   DEBUG({
diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index a1817ea1926ce59b57a3b039a751d9fc2385ad6e..e5fe7b5091aa43a94d91f7e5d15bdf3d34e7b751 100644
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -1621,6 +1621,17 @@ TEST_F(FormatTest, SplitsLongLinesInComments) {
                    "   */",
                    getLLVMStyleWithColumns(20)));
 
+  EXPECT_EQ("/**\n"
+            " * multiline block\n"
+            " * comment\n"
+            " *\n"
+            " */",
+            format("/**\n"
+                   " * multiline block comment\n"
+                   " *\n"
+                   " */",
+                   getLLVMStyleWithColumns(20)));
+
   EXPECT_EQ("/*\n"
             "\n"
             "\n"
@@ -6525,7 +6536,7 @@ TEST_F(FormatTest, BlockComments) {
   EXPECT_EQ("/*\n"
             "*\n"
             " * aaaaaa\n"
-            "*aaaaaa\n"
+            " * aaaaaa\n"
             "*/",
             format("/*\n"
                    "*\n"