diff --git a/Password.h b/Password.h
index 5fa6591..dfa6471 100644
--- a/Password.h
+++ b/Password.h
@@ -15,5 +15,11 @@ class Password
   'z' and any ASCII characters are allowed.
   */
   int count_leading_characters(string word);
+
+  /*
+  receives a string and returns whether it has both at least one upper-case
+  letter and at least one lower-case letter
+  */
+  bool has_mixed_case(string);
 };
 #endif