diff --git a/test/Preprocessor/cxx_not_eq.cpp b/test/Preprocessor/cxx_not_eq.cpp
new file mode 100644
index 0000000..b0be7b3
--- /dev/null
+++ b/test/Preprocessor/cxx_not_eq.cpp
@@ -0,0 +1,16 @@
+// RUN: clang -DA=1 -DB=1 -E %s | grep 'int a = 927 == 927' &&
+// RUN: clang -E %s | grep 'int a = 927 == 927' &&
+// RUN: clang -DA=1 -DB=2 -E %s | grep 'int a = 37 == 37'
+#if A not_eq B
+#define X 37
+#else
+#define X 927
+#endif
+
+#if A != B
+#define Y 37
+#else
+#define Y 927
+#endif
+
+int a = X == Y;