diff --git a/clang/lib/Frontend/Rewrite/RewriteModernObjC.cpp b/clang/lib/Frontend/Rewrite/RewriteModernObjC.cpp
index 3c48de2b4aa5..bcfba2266810 100644
--- a/clang/lib/Frontend/Rewrite/RewriteModernObjC.cpp
+++ b/clang/lib/Frontend/Rewrite/RewriteModernObjC.cpp
@@ -5526,6 +5526,10 @@ Stmt *RewriteModernObjC::SynthBlockInitExpr(BlockExpr *Exp,
                              VK_RValue, OK_Ordinary, SourceLocation());
   NewRep = NoTypeInfoCStyleCastExpr(Context, FType, CK_BitCast,
                                     NewRep);
+  // Put Paren around the call.
+  NewRep = new (Context) ParenExpr(SourceLocation(), SourceLocation(),
+                                   NewRep);
+  
   BlockDeclRefs.clear();
   BlockByRefDecls.clear();
   BlockByRefDeclsPtrSet.clear();
diff --git a/clang/test/Rewriter/rewrite-block-literal.mm b/clang/test/Rewriter/rewrite-block-literal.mm
index 43f581125ba0..cde6efcbf29d 100644
--- a/clang/test/Rewriter/rewrite-block-literal.mm
+++ b/clang/test/Rewriter/rewrite-block-literal.mm
@@ -70,7 +70,7 @@ static int global_x = 10;
 void (^global_block)(void) = ^{ printf("global x is %d\n", global_x); };
 
 // CHECK: static __global_block_block_impl_0 __global_global_block_block_impl_0((void *)__global_block_block_func_0, &__global_block_block_desc_0_DATA);
-// CHECK: void (*global_block)(void) = (void (*)())&__global_global_block_block_impl_0;
+// CHECK: void (*global_block)(void) = ((void (*)())&__global_global_block_block_impl_0);
 
 typedef void (^void_block_t)(void);
 
diff --git a/clang/test/Rewriter/rewrite-modern-block.mm b/clang/test/Rewriter/rewrite-modern-block.mm
index 23029654c984..926ee36f1a4a 100644
--- a/clang/test/Rewriter/rewrite-modern-block.mm
+++ b/clang/test/Rewriter/rewrite-modern-block.mm
@@ -63,3 +63,6 @@ z w(int loc, int len);
     options &= ~(1 | 2);
 }
 @end
+
+// rdar://18799145
+int Test18799145() { return ^(){return 0;}(); }
diff --git a/clang/test/Rewriter/rewrite-modern-captured-nested-bvar.mm b/clang/test/Rewriter/rewrite-modern-captured-nested-bvar.mm
index a8fd18073372..be7548c778ab 100644
--- a/clang/test/Rewriter/rewrite-modern-captured-nested-bvar.mm
+++ b/clang/test/Rewriter/rewrite-modern-captured-nested-bvar.mm
@@ -32,4 +32,4 @@ int main() {
 
 // CHECK 2: (__Block_byref_BYREF_VAR_CHECK_0 *)BYREF_VAR_CHECK
 // CHECK: {(void*)0,(__Block_byref_BYREF_VAR_CHECK_0 *)&BYREF_VAR_CHECK, 0, sizeof(__Block_byref_BYREF_VAR_CHECK_0), 'a'}
-// CHECK: __Block_byref_BYREF_VAR_CHECK_0 *)&BYREF_VAR_CHECK, (__Block_byref_d_1 *)&d, 570425344));
+// CHECK: __Block_byref_BYREF_VAR_CHECK_0 *)&BYREF_VAR_CHECK, (__Block_byref_d_1 *)&d, 570425344)));