diff --git a/quicklisp/misc.lisp b/quicklisp/misc.lisp
index 2cfabce..aab4e79 100644
--- a/quicklisp/misc.lisp
+++ b/quicklisp/misc.lisp
@@ -14,6 +14,7 @@
 
 (defun who-depends-on (system-name)
   "Return a list of names of systems that depend on SYSTEM-NAME."
+  (setf system-name (string-downcase system-name))
   (loop for system in (provided-systems t)
         when (member system-name (required-systems system) :test 'string=)
         collect (name system)))