diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp
index 886b212..3646e27 100644
--- a/clang/lib/Frontend/InitPreprocessor.cpp
+++ b/clang/lib/Frontend/InitPreprocessor.cpp
@@ -641,6 +641,16 @@
                         "__attribute__((objc_ownership(none)))");
   }
 
+  // OpenMP definition
+  if (LangOpts.OpenMP) {
+    // OpenMP 2.2: 
+    //   In implementations that support a preprocessor, the _OPENMP
+    //   macro name is defined to have the decimal value yyyymm where
+    //   yyyy and mm are the year and the month designations of the
+    //   version of the OpenMP API that the implementation support.
+    Builder.defineMacro("_OPENMP", "201107");
+  }
+
   // Get other target #defines.
   TI.getTargetDefines(LangOpts, Builder);
 }