diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index 73bd2b6..f05b9c1 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -3847,6 +3847,7 @@
     if (Opts.CPlusPlus)
       Builder.defineMacro("_GNU_SOURCE");
 
+    Builder.defineMacro("__LITTLE_ENDIAN__");
     Builder.defineMacro("__native_client__");
     getArchDefines(Opts, Builder);
   }
diff --git a/test/Driver/le32-unknown-nacl.cpp b/test/Driver/le32-unknown-nacl.cpp
index 803fac1..f68b220 100644
--- a/test/Driver/le32-unknown-nacl.cpp
+++ b/test/Driver/le32-unknown-nacl.cpp
@@ -40,6 +40,11 @@
 // CHECK: @align_vl = global i32 4
 int align_vl = __alignof(va_list);
 
+// CHECK: __LITTLE_ENDIAN__defined
+#ifdef __LITTLE_ENDIAN__
+void __LITTLE_ENDIAN__defined() {}
+#endif
+
 // CHECK: __native_client__defined
 #ifdef __native_client__
 void __native_client__defined() {}