diff --git a/lisp/install.ros b/lisp/install.ros
index 2be6582..33ec5b6 100644
--- a/lisp/install.ros
+++ b/lisp/install.ros
@@ -15,8 +15,6 @@ exec ros -Q +R -L sbcl-bin -- $0 "$@"
 (in-package :ros.script.install.3671936092)
 
 (defun main (&rest argv)
-  (let ((asdf:*system-definition-search-functions*
-          (remove 'roswell-installable-searcher asdf:*system-definition-search-functions*)))
-    (install argv)))
+  (install argv))
 
 ;;; vim: set ft=lisp lisp:
diff --git a/lisp/patch-quicklisp.lisp b/lisp/patch-quicklisp.lisp
index e694928..c892cb5 100644
--- a/lisp/patch-quicklisp.lisp
+++ b/lisp/patch-quicklisp.lisp
@@ -35,6 +35,7 @@
 
 (defun roswell-installable-searcher (system-name)
   (let ((name (roswell-installed-system-name system-name))
+        (env "ROSINSTALL")
         pname)
     (and
      name
@@ -42,7 +43,13 @@
             (asdf:find-system pname nil)))
      (prog1
          (or (quicklisp-client:local-projects-searcher name)
-             (progn
+             (unless (find system-name (loop for ar = (ros:getenv env) then (subseq ar (1+ p))
+                                             for p = (position #\, ar)
+                                             for arg = (if p (subseq ar 0 p) ar)
+                                             collect arg
+                                             while p)
+                           :test 'equal)
+               (roswell.util:setenv env (format nil "~A,~A" system-name (ros:getenv env)))
                (roswell:roswell `("install" ,system-name))
                (quicklisp-client:register-local-projects)
                (quicklisp-client:local-projects-searcher name))