diff --git a/racket/lib/collects/mzlib/contract.rkt b/pkgs/compatibility-lib/mzlib/contract.rkt
similarity index 100%
rename from racket/lib/collects/mzlib/contract.rkt
rename to pkgs/compatibility-lib/mzlib/contract.rkt
diff --git a/racket/lib/collects/mzlib/private/contract-arr-checks.rkt b/pkgs/compatibility-lib/mzlib/private/contract-arr-checks.rkt
similarity index 100%
rename from racket/lib/collects/mzlib/private/contract-arr-checks.rkt
rename to pkgs/compatibility-lib/mzlib/private/contract-arr-checks.rkt
diff --git a/racket/lib/collects/mzlib/private/contract-arr-obj-helpers.rkt b/pkgs/compatibility-lib/mzlib/private/contract-arr-obj-helpers.rkt
similarity index 100%
rename from racket/lib/collects/mzlib/private/contract-arr-obj-helpers.rkt
rename to pkgs/compatibility-lib/mzlib/private/contract-arr-obj-helpers.rkt
diff --git a/racket/lib/collects/mzlib/private/contract-arrow.rkt b/pkgs/compatibility-lib/mzlib/private/contract-arrow.rkt
similarity index 100%
rename from racket/lib/collects/mzlib/private/contract-arrow.rkt
rename to pkgs/compatibility-lib/mzlib/private/contract-arrow.rkt
diff --git a/racket/lib/collects/mzlib/private/contract-define.rkt b/pkgs/compatibility-lib/mzlib/private/contract-define.rkt
similarity index 100%
rename from racket/lib/collects/mzlib/private/contract-define.rkt
rename to pkgs/compatibility-lib/mzlib/private/contract-define.rkt
diff --git a/racket/lib/collects/mzlib/private/contract-mutable.rkt b/pkgs/compatibility-lib/mzlib/private/contract-mutable.rkt
similarity index 100%
rename from racket/lib/collects/mzlib/private/contract-mutable.rkt
rename to pkgs/compatibility-lib/mzlib/private/contract-mutable.rkt
diff --git a/racket/lib/collects/mzlib/private/contract-object.rkt b/pkgs/compatibility-lib/mzlib/private/contract-object.rkt
similarity index 100%
rename from racket/lib/collects/mzlib/private/contract-object.rkt
rename to pkgs/compatibility-lib/mzlib/private/contract-object.rkt
diff --git a/racket/lib/collects/mzlib/private/contract-struct.rkt b/pkgs/compatibility-lib/mzlib/private/contract-struct.rkt
similarity index 100%
rename from racket/lib/collects/mzlib/private/contract-struct.rkt
rename to pkgs/compatibility-lib/mzlib/private/contract-struct.rkt