diff --git a/dlib/dlib.hh b/dlib/dlib.hh
index 712d636..31a156c 100644
--- a/dlib/dlib.hh
+++ b/dlib/dlib.hh
@@ -16,6 +16,7 @@ struct CharPtrNoStringConversion
 	char *ptr= nullptr;
 
 	operator char *() const noexcept { return ptr; }
+	operator std::string () const= delete;
 };
 
 #ifdef __cplusplus