diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index cd3bf17..fc95acc 100644
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -1859,6 +1859,7 @@
   verifyFormat("class MACRO(X) Z {\n} n;");
   verifyFormat("class __attribute__(X) Z {\n} n;");
   verifyFormat("class __declspec(X) Z {\n} n;");
+  verifyFormat("class A##B##C {\n} n;");
 
   // Redefinition from nested context:
   verifyFormat("class A::B::C {\n} n;");