diff --git a/include/clang/Basic/DiagnosticKinds.def b/include/clang/Basic/DiagnosticKinds.def
index 03787df..20337f0 100644
--- a/include/clang/Basic/DiagnosticKinds.def
+++ b/include/clang/Basic/DiagnosticKinds.def
@@ -448,6 +448,8 @@
      "prefix attribute must be followed by an interface or protocol")
 DIAG(err_objc_property_attr_mutually_exclusive, ERROR,
      "property attributes '%0' and '%1' are mutually exclusive")
+DIAG(warn_objc_property_attr_mutually_exclusive, WARNING,
+     "property attributes '%0' and '%1' are mutually exclusive")
 DIAG(warn_objc_property_no_assignment_attribute, WARNING,
      "no 'assign', 'retain', or 'copy' attribute is specified - 'assign' is assumed")
 DIAG(warn_objc_property_default_assign_on_object, WARNING,
diff --git a/lib/Sema/SemaDeclObjC.cpp b/lib/Sema/SemaDeclObjC.cpp
index 828e1fc..5e9e2b2 100644
--- a/lib/Sema/SemaDeclObjC.cpp
+++ b/lib/Sema/SemaDeclObjC.cpp
@@ -1299,9 +1299,10 @@
                          (Attributes & ObjCDeclSpec::DQ_PR_copy) ?
                           "copy" : "retain";
                          
-    Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
+    Diag(Loc, (Attributes & (ObjCDeclSpec::DQ_PR_readwrite)) ? 
+                 diag::err_objc_property_attr_mutually_exclusive :
+                 diag::warn_objc_property_attr_mutually_exclusive)
       << "readonly" << which;
-    return;
   }
 
   // Check for copy or retain on non-object types.
diff --git a/test/SemaObjC/property-12.m b/test/SemaObjC/property-12.m
index bdd026d..659ffa1 100644
--- a/test/SemaObjC/property-12.m
+++ b/test/SemaObjC/property-12.m
@@ -1,15 +1,15 @@
 // RUN: clang -fsyntax-only -verify %s
 
 @protocol P0
-@property(readonly,assign) id X; // expected-error {{property attributes 'readonly' and 'assign' are mutually exclusive}}
+@property(readonly,assign) id X; // expected-warning {{property attributes 'readonly' and 'assign' are mutually exclusive}}
 @end
 
 @protocol P1
-@property(readonly,retain) id X; // expected-error {{property attributes 'readonly' and 'retain' are mutually exclusive}}
+@property(readonly,retain) id X; // expected-warning {{property attributes 'readonly' and 'retain' are mutually exclusive}}
 @end
 
 @protocol P2
-@property(readonly,copy) id X; // expected-error {{property attributes 'readonly' and 'copy' are mutually exclusive}}
+@property(readonly,copy) id X; // expected-warning {{property attributes 'readonly' and 'copy' are mutually exclusive}}
 @end
 
 @protocol P3