diff --git a/gnu/packages/gnome.scm b/gnu/packages/gnome.scm
index d6fb1a8c14f..20ee4fe3662 100644
--- a/gnu/packages/gnome.scm
+++ b/gnu/packages/gnome.scm
@@ -3661,6 +3661,7 @@ for dealing with different structured file formats.")
         (guix build gnu-build-system)
         (guix build utils))
       #:phases
+      (with-extensions (list (cargo-guile-json))
       #~(modify-phases %standard-phases
           (add-after 'unpack 'patch-gdk-pixbuf-thumbnailer
             (lambda* (#:key inputs #:allow-other-keys)
@@ -3712,7 +3713,7 @@ for dealing with different structured file formats.")
                '(unpack-rust-crates
                  configure
                  check-for-pregenerated-files
-                 patch-cargo-checksums)))))))
+                 patch-cargo-checksums))))))))
     (native-inputs
      (append
       (list gdk-pixbuf