diff --git a/lib/CodeGen/CGObjC.cpp b/lib/CodeGen/CGObjC.cpp
index a47c56f..c90e4ec 100644
--- a/lib/CodeGen/CGObjC.cpp
+++ b/lib/CodeGen/CGObjC.cpp
@@ -810,6 +810,10 @@
   PropertyImplStrategy strategy(CGM, propImpl);
   switch (strategy.getKind()) {
   case PropertyImplStrategy::Native: {
+    // We don't need to do anything for a zero-size struct.
+    if (strategy.getIvarSize().isZero())
+      return;
+
     LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, 0);
 
     // Currently, all atomic accesses have to be through integer
@@ -1068,6 +1072,10 @@
   PropertyImplStrategy strategy(CGM, propImpl);
   switch (strategy.getKind()) {
   case PropertyImplStrategy::Native: {
+    // We don't need to do anything for a zero-size struct.
+    if (strategy.getIvarSize().isZero())
+      return;
+
     llvm::Value *argAddr = LocalDeclMap[*setterMethod->param_begin()];
 
     LValue ivarLValue =
diff --git a/test/CodeGenObjC/atomic-aggregate-property.m b/test/CodeGenObjC/atomic-aggregate-property.m
index 978299b..878255b 100644
--- a/test/CodeGenObjC/atomic-aggregate-property.m
+++ b/test/CodeGenObjC/atomic-aggregate-property.m
@@ -1,6 +1,7 @@
 // RUN: %clang_cc1 -triple x86_64-apple-darwin10  -fobjc-gc -emit-llvm -o - %s | FileCheck -check-prefix LP64 %s
 // RUN: %clang_cc1 -x objective-c++ -triple x86_64-apple-darwin10  -fobjc-gc -emit-llvm -o - %s | FileCheck -check-prefix LP64 %s
 // rdar: // 7849824
+// <rdar://problem/12547611>
 
 struct s {
   double a, b, c, d;  
@@ -12,16 +13,20 @@
     id k;
 };
 
+struct s2 {};
+
 @interface A 
 @property (readwrite) double x;
 @property (readwrite) struct s y;
 @property (nonatomic, readwrite) struct s1 z;
+@property (readwrite) struct s2 a;
 @end
 
 @implementation A
 @synthesize x;
 @synthesize y;
 @synthesize z;
+@synthesize a;
 @end
 // CHECK-LP64: define internal double @"\01-[A x]"(
 // CHECK-LP64: load atomic i64* {{%.*}} unordered, align 8
@@ -40,3 +45,9 @@
 
 // CHECK-LP64: define internal void @"\01-[A setZ:]"(
 // CHECK-LP64: call i8* @objc_memmove_collectable(
+
+// CHECK-LP64: define internal void @"\01-[A a]"(
+// (do nothing)
+
+// CHECK-LP64: define internal void @"\01-[A setA:]"(
+// (do nothing)