diff --git a/core/src/nixpkgs.sld b/core/src/nixpkgs.sld
index 2fd932c..3b22b88 100644
--- a/core/src/nixpkgs.sld
+++ b/core/src/nixpkgs.sld
@@ -112,6 +112,7 @@
       (define processor
        (string-append "if [ -e \"$NIX_ATTRS_SH_FILE\" ]; then source \"$NIX_ATTRS_SH_FILE\"; fi
                   export IN_NIX_SHELL=impure; export dontAddDisableDepTrack=1
+                  export NIX_OUTPATH_USED_AS_RANDOM_SEED=/nix/store/zilchzilchzilchzilch
                   if [[ -n $stdenv ]]; then
                     source $stdenv/setup
                   fi
@@ -123,10 +124,9 @@
                     str=\"${str//$'\\r'/\\\\r}\"
                     printf '\"%s\"' \"$str\"
                   }
-                  out=" (make-placeholder "out") "
-                  printf '(' > $out
+                  printf '(' > $zilch_out
                   __run() {
-                    declare -p | while read __line; do
+                    declare -p | grep -v zilch_out | while read __line; do
                       if ! [[ $__line =~ ^declare\\ (-[^ ])\\ ([^=]*) ]]; then continue; fi
                       local __varname=\"${BASH_REMATCH[2]}\"
                       if [[ \"${BASH_REMATCH[1]}\" == -x ]]; then
@@ -138,22 +138,38 @@
                       fi
                     done
                   }
-                  __run >> $out
-                  printf ')' >> $out\n"))
+                  __run >> $zilch_out
+                  printf ')' >> $zilch_out\n"))
+      (define output-names (map car (derivation-outputs drv)))
       (define new-env (list))
+
+      (define base-placeholder "zilchplaceholderdonotuseanywhere-")
+      (define name (derivation-name drv))
+      (define placeholders
+       (map
+         (lambda (l)
+          (cons (car l)
+           (string-append "/nix/store/" (car l) (string-copy base-placeholder (string-length (car l))) name (if (string=? (car l) "out") "" (string-append "-" (car l))))))
+         (derivation-outputs drv)))
       (for-each
         (lambda (kv)
-          (unless (member (car kv) '("out" "name" "builder" "system" "allowedReferences" "disallowedReferences" "allowedRequisites" "disallowedRequisites") string=?) (set! new-env (cons kv new-env))))
+          (cond
+           ((member (car kv) '("name" "src" "builder" "system" "allowedReferences" "disallowedReferences" "allowedRequisites" "disallowedRequisites") string=?)
+            #f)
+           ((member (car kv) output-names string=?)
+            (set! new-env (cons (assoc (car kv) placeholders) new-env)))
+           (else
+            (set! new-env (cons kv new-env)))))
         (derivation-env drv))
       (define is-ca-derivation (symbol? (derivation-output-hash (cdar (derivation-outputs drv)))))
       (define out-drv
-       ((if is-ca-derivation make-ca-derivation make-input-addressed-derivation) "zilch-env"
+       (make-ca-derivation "zilch-env"
         (derivation-system drv)
         (derivation-input-drvs drv)
         (derivation-input-src drv)
         (list (derivation-builder drv) "-c" processor)
         new-env
-        '("out")))
-      (define environment (call-with-port (store-path-open (make-store-path out-drv "out" #f)) (lambda (p) (read p))))
-      (make-zexp (lambda () (zexp-context-register-items (list (list out-drv "out")) '()) environment) (lambda (p) (fprintf p "<shell environment for ~A>" (derivation-path drv)))))))
+        '("zilch_out")))
+      (define environment (call-with-port (store-path-open (make-store-path out-drv "zilch_out" #f)) (lambda (p) (read p))))
+      (make-zexp (lambda () (zexp-context-register-items (list (list out-drv "zilch_out")) '()) environment) (lambda (p) (fprintf p "<shell environment for ~A>" (derivation-path drv)))))))