diff --git a/test/testbufferoverrun.cpp b/test/testbufferoverrun.cpp
index eac0080cb..6f386366e 100644
--- a/test/testbufferoverrun.cpp
+++ b/test/testbufferoverrun.cpp
@@ -898,6 +898,7 @@ private:
         ASSERT_EQUALS(6, CheckBufferOverrun::count("%-5s"));
         ASSERT_EQUALS(2, CheckBufferOverrun::count("\\\""));
         TODO_ASSERT_EQUALS(6, CheckBufferOverrun::count("Hello\\0Text"));
+        TODO_ASSERT_EQUALS(2, CheckBufferOverrun::count("%%"));
     }
 
     void strncpy1()