diff --git a/README b/README
index c4cf8f0..18aa37c 100644
--- a/README
+++ b/README
@@ -12,6 +12,7 @@ Cuirass currently depends on the following packages:
   - Guile-JSON 3.x
   - Guile-SQLite3
   - Guile-Git
+  - Guile-zlib
   - Fibers
 
 A convenient way to install those dependencies is to install Guix and execute
diff --git a/build-aux/guix.scm b/build-aux/guix.scm
index c963b05..2dbdd6e 100644
--- a/build-aux/guix.scm
+++ b/build-aux/guix.scm
@@ -68,9 +68,11 @@
            (let* ((out    (assoc-ref outputs "out"))
                   (json   (assoc-ref inputs "guile-json"))
                   (sqlite (assoc-ref inputs "guile-sqlite3"))
+                  (zlib   (assoc-ref inputs "guile-zlib"))
                   (guix   (assoc-ref inputs "guix"))
                   (mods   (string-append json "/share/guile/site/3.0:"
                                          sqlite "/share/guile/site/3.0:"
+                                         zlib "/share/guile/site/3.0:"
                                          guix "/share/guile/site/3.0")))
              (wrap-program (string-append out "/bin/cuirass")
                `("GUILE_LOAD_PATH" ":" prefix (,mods))
@@ -82,6 +84,7 @@
           "guile-json"
           "guile-sqlite3"
           "guile-git"
+          "guile-zlib"
           "guix")))
   (native-inputs
    (map spec+package-list
diff --git a/src/cuirass/base.scm b/src/cuirass/base.scm
index 51bca6b..7a566d3 100644
--- a/src/cuirass/base.scm
+++ b/src/cuirass/base.scm
@@ -32,7 +32,7 @@
   #:use-module (guix store)
   #:use-module (guix git)
   #:use-module (guix cache)
-  #:use-module (guix zlib)
+  #:use-module (zlib)
   #:use-module ((guix config) #:select (%state-directory))
   #:use-module (git)
   #:use-module (ice-9 binary-ports)