diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp
index f8b912e..ea5b48c 100644
--- a/clang/lib/Frontend/InitPreprocessor.cpp
+++ b/clang/lib/Frontend/InitPreprocessor.cpp
@@ -435,6 +435,9 @@
     Builder.defineMacro("CL_VERSION_1_2", "120");
     Builder.defineMacro("CL_VERSION_2_0", "200");
 
+    if (TI.isLittleEndian())
+      Builder.defineMacro("__ENDIAN_LITTLE__");
+
     if (LangOpts.FastRelaxedMath)
       Builder.defineMacro("__FAST_RELAXED_MATH__");
   }