diff --git a/Source/CTest/cmCTestBuildAndTestHandler.cxx b/Source/CTest/cmCTestBuildAndTestHandler.cxx
index ece46973e..41db042a8 100644
--- a/Source/CTest/cmCTestBuildAndTestHandler.cxx
+++ b/Source/CTest/cmCTestBuildAndTestHandler.cxx
@@ -70,7 +70,7 @@ int cmCTestBuildAndTestHandler::RunCMake(std::string* outstring,
     }
   if(!this->BuildGeneratorPlatform.empty())
     {
-    std::string platform = "-DCMAKE_GENERATOR_PLATFORM=";
+    std::string platform = "-A";
     platform += this->BuildGeneratorPlatform;
     args.push_back(platform);
     }
diff --git a/Source/CTest/cmCTestConfigureCommand.cxx b/Source/CTest/cmCTestConfigureCommand.cxx
index 8ab503702..ef62fd372 100644
--- a/Source/CTest/cmCTestConfigureCommand.cxx
+++ b/Source/CTest/cmCTestConfigureCommand.cxx
@@ -122,7 +122,7 @@ cmCTestGenericHandler* cmCTestConfigureCommand::InitializeHandler()
         this->Makefile->GetDefinition("CTEST_CMAKE_GENERATOR_PLATFORM");
       if(cmakeGeneratorPlatform && *cmakeGeneratorPlatform)
         {
-        cmakeConfigureCommand += " \"-DCMAKE_GENERATOR_PLATFORM=";
+        cmakeConfigureCommand += " \"-A";
         cmakeConfigureCommand += cmakeGeneratorPlatform;
         cmakeConfigureCommand += "\"";
         }