Index: clang/lib/Format/Format.cpp
===================================================================
--- clang/lib/Format/Format.cpp
+++ clang/lib/Format/Format.cpp
@@ -1786,9 +1786,11 @@
         Code.substr(Prev, (Pos != StringRef::npos ? Pos : Code.size()) - Prev);
 
     StringRef Trimmed = Line.trim();
-    if (Trimmed == "// clang-format off")
+    if (Trimmed == "// clang-format off" ||
+        Trimmed.startswith("/* clang-format off"))
       FormattingOff = true;
-    else if (Trimmed == "// clang-format on")
+    else if (Trimmed == "// clang-format on" ||
+             Trimmed.startswith("/* clang-format on"))
       FormattingOff = false;
 
     const bool EmptyLineSkipped =
Index: clang/unittests/Format/SortIncludesTest.cpp
===================================================================
--- clang/unittests/Format/SortIncludesTest.cpp
+++ clang/unittests/Format/SortIncludesTest.cpp
@@ -117,6 +117,25 @@
                  "// clang-format on\n"));
 }
 
+TEST_F(SortIncludesTest, SupportClangFormatOffCStyle) {
+  EXPECT_EQ("#include <a>\n"
+            "#include <b>\n"
+            "#include <c>\n"
+            "/* clang-format off */\n"
+            "#include <b>\n"
+            "#include <a>\n"
+            "#include <c>\n"
+            "/* clang-format on */\n",
+            sort("#include <b>\n"
+                 "#include <a>\n"
+                 "#include <c>\n"
+                 "/* clang-format off */\n"
+                 "#include <b>\n"
+                 "#include <a>\n"
+                 "#include <c>\n"
+                 "/* clang-format on */\n"));
+}
+
 TEST_F(SortIncludesTest, IncludeSortingCanBeDisabled) {
   FmtStyle.SortIncludes = false;
   EXPECT_EQ("#include \"a.h\"\n"