diff --git a/BUILD b/BUILD
index b2229a1..c9ab8fc 100644
--- a/BUILD
+++ b/BUILD
@@ -4,19 +4,21 @@ objc_library(
     name = "MOLXPCConnection",
     srcs = ["Source/MOLXPCConnection/MOLXPCConnection.m"],
     hdrs = ["Source/MOLXPCConnection/MOLXPCConnection.h"],
+    copts = ["-Wunguarded-availability"],
     includes = ["Source"],
     sdk_frameworks = ["Security"],
-    deps = ["@MOLCodesignChecker//:MOLCodesignChecker"],
     visibility = ["//visibility:public"],
+    deps = ["@MOLCodesignChecker"],
 )
 
 objc_library(
     name = "MOLXPCConnectionTestsLib",
     testonly = 1,
     srcs = ["Tests/MOLXPCConnectionTests.m"],
+    copts = ["-Wunguarded-availability"],
     deps = [
         ":MOLXPCConnection",
-        "@OCMock//:OCMock",
+        "@OCMock",
     ],
 )
 
diff --git a/MOLXPCConnection.podspec b/MOLXPCConnection.podspec
index 45b8f92..6d54a25 100644
--- a/MOLXPCConnection.podspec
+++ b/MOLXPCConnection.podspec
@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
   s.name         = 'MOLXPCConnection'
   s.version      = '2.1'
-  s.platform     = :osx, '10.11'
+  s.platform     = :osx, '10.9'
   s.license      = { :type => 'Apache 2.0', :file => 'LICENSE' }
   s.homepage     = 'https://github.com/google/macops-molxpcconnection'
   s.authors      = { 'Google Macops' => 'macops-external@google.com' }
@@ -10,4 +10,5 @@ Pod::Spec.new do |s|
                      :tag => "v#{s.version}" }
   s.source_files = 'Source/MOLXPCConnection/*.{h,m}'
   s.dependency 'MOLCodesignChecker', '~> 2.2'
+  s.compiler_flags = '-Wunguarded-availability'
 end
diff --git a/Source/MOLXPCConnection/MOLXPCConnection.h b/Source/MOLXPCConnection/MOLXPCConnection.h
index 59a2d85..7e043d1 100644
--- a/Source/MOLXPCConnection/MOLXPCConnection.h
+++ b/Source/MOLXPCConnection/MOLXPCConnection.h
@@ -119,7 +119,7 @@
  @note If the connection to the server failed, this will be nil, so you can safely send messages
  and rely on the invalidationHandler for handling the failure.
  */
-@property(readonly, nonatomic, nullable) id synchronousRemoteObjectProxy;
+@property(readonly, nonatomic, nullable) id synchronousRemoteObjectProxy API_AVAILABLE(macos(10.11));
 
 /**
  The privileged interface this object exports. (server)
diff --git a/Tests/MOLXPCConnectionTests.m b/Tests/MOLXPCConnectionTests.m
index c5951f2..09beafe 100644
--- a/Tests/MOLXPCConnectionTests.m
+++ b/Tests/MOLXPCConnectionTests.m
@@ -25,8 +25,30 @@ @interface MOLXPCConnectionTest : XCTestCase
 @protocol DummyXPCProtocol
 @end
 
+@protocol DeepThoughtProtocol
+- (void)theAnswerToLifeTheUniverseAndEverything:(void(^)(int))reply;
+@end
+
+@interface DeepThought : NSObject<DeepThoughtProtocol>
+@end
+
+@implementation DeepThought
+- (void)theAnswerToLifeTheUniverseAndEverything:(void(^)(int))reply {
+  reply(42);
+}
+@end
+
 @implementation MOLXPCConnectionTest
 
+- (NSXPCInterface *)deepThoughtInterface {
+  static NSXPCInterface *interface;
+  static dispatch_once_t onceToken;
+  dispatch_once(&onceToken, ^{
+    interface = [NSXPCInterface interfaceWithProtocol:@protocol(DeepThoughtProtocol)];
+  });
+  return interface;
+}
+
 - (void)testPlainInit {
   XCTAssertThrows([[MOLXPCConnection alloc] init]);
 }
@@ -127,4 +149,21 @@ - (void)testConnectionInterruption {
   [self waitForExpectationsWithTimeout:1.0 handler:NULL];
 }
 
+- (void)testSynchronous {
+  NSXPCListener *listener = [NSXPCListener anonymousListener];
+  MOLXPCConnection *sutServer = [[MOLXPCConnection alloc] initServerWithListener:listener];
+  sutServer.unprivilegedInterface = [self deepThoughtInterface];
+  sutServer.exportedObject = [[DeepThought alloc] init];
+  [sutServer resume];
+
+   __block int answer = 0;
+  MOLXPCConnection *sutClient = [[MOLXPCConnection alloc] initClientWithListener:listener.endpoint];
+  sutClient.remoteInterface = [self deepThoughtInterface];
+  [sutClient resume];
+  [[sutClient synchronousRemoteObjectProxy] theAnswerToLifeTheUniverseAndEverything:^(int reply) {
+    answer = reply;
+  }];
+  XCTAssertEqual(answer, 42);
+}
+
 @end