Index: include/clang/Format/Format.h
===================================================================
--- include/clang/Format/Format.h
+++ include/clang/Format/Format.h
@@ -651,7 +651,9 @@
     ///   }
     /// \endcode
     bool AfterNamespace;
-    /// \brief Wrap ObjC definitions (``@autoreleasepool``, interfaces, ..).
+    /// \brief Wrap ObjC definitions (interfaces, implementations...).
+    /// \note @autoreleasepool and @synchronized blocks are wrapped
+    /// according to `AfterControlStatement` flag.
     bool AfterObjCDeclaration;
     /// \brief Wrap struct definitions.
     /// \code
Index: lib/Format/UnwrappedLineFormatter.cpp
===================================================================
--- lib/Format/UnwrappedLineFormatter.cpp
+++ lib/Format/UnwrappedLineFormatter.cpp
@@ -314,6 +314,14 @@
       }
       return MergedLines;
     }
+    // Don't merge block with left brace wrapped after ObjC special blocks
+    if (TheLine->First->is(tok::l_brace) && I != AnnotatedLines.begin() &&
+        I[-1]->First->is(tok::at) && I[-1]->First->Next) {
+      tok::ObjCKeywordKind kwId = I[-1]->First->Next->Tok.getObjCKeywordID();
+      if (kwId == clang::tok::objc_autoreleasepool ||
+          kwId == clang::tok::objc_synchronized)
+        return 0;
+    }
     // Try to merge a block with left brace wrapped that wasn't yet covered
     if (TheLine->Last->is(tok::l_brace)) {
       return !Style.BraceWrapping.AfterFunction ||
Index: lib/Format/UnwrappedLineParser.cpp
===================================================================
--- lib/Format/UnwrappedLineParser.cpp
+++ lib/Format/UnwrappedLineParser.cpp
@@ -1115,7 +1115,7 @@
       case tok::objc_autoreleasepool:
         nextToken();
         if (FormatTok->Tok.is(tok::l_brace)) {
-          if (Style.BraceWrapping.AfterObjCDeclaration)
+          if (Style.BraceWrapping.AfterControlStatement)
             addUnwrappedLine();
           parseBlock(/*MustBeDeclaration=*/false);
         }
@@ -1127,7 +1127,7 @@
            // Skip synchronization object
            parseParens();
         if (FormatTok->Tok.is(tok::l_brace)) {
-          if (Style.BraceWrapping.AfterObjCDeclaration)
+          if (Style.BraceWrapping.AfterControlStatement)
             addUnwrappedLine();
           parseBlock(/*MustBeDeclaration=*/false);
         }
Index: unittests/Format/FormatTestObjC.cpp
===================================================================
--- unittests/Format/FormatTestObjC.cpp
+++ unittests/Format/FormatTestObjC.cpp
@@ -178,7 +178,8 @@
                "@autoreleasepool {\n"
                "  f();\n"
                "}\n");
-  Style.BreakBeforeBraces = FormatStyle::BS_Allman;
+  Style.BreakBeforeBraces = FormatStyle::BS_Custom;
+  Style.BraceWrapping.AfterControlStatement = true;
   verifyFormat("@autoreleasepool\n"
                "{\n"
                "  f();\n"
@@ -196,7 +197,8 @@
                "@synchronized(self) {\n"
                "  f();\n"
                "}\n");
-  Style.BreakBeforeBraces = FormatStyle::BS_Allman;
+  Style.BreakBeforeBraces = FormatStyle::BS_Custom;
+  Style.BraceWrapping.AfterControlStatement = true;
   verifyFormat("@synchronized(self)\n"
                "{\n"
                "  f();\n"