1 files changed, 11 insertions, 0 deletions
diff --git a/libcxx/test/strings/basic.string/string.access/back.pass.cpp b/libcxx/test/strings/basic.string/string.access/back.pass.cpp
index f241d4d9125..9c4800e3abf 100644
--- a/libcxx/test/strings/basic.string/string.access/back.pass.cpp
+++ b/libcxx/test/strings/basic.string/string.access/back.pass.cpp
@@ -12,6 +12,10 @@
 // const charT& back() const;
 //       charT& back();
 
+#ifdef _LIBCPP_DEBUG2
+#define _LIBCPP_ASSERT(x, m) ((x) ? (void)0 : std::exit(0))
+#endif
+
 #include <string>
 #include <cassert>
 
@@ -42,4 +46,11 @@ int main()
     test(S("1234567890123456789012345678901234567890"));
     }
 #endif
+#ifdef _LIBCPP_DEBUG2
+    {
+        std::string s;
+        char c = s.back();
+        assert(false);
+    }
+#endif
 }