diff --git a/Makefile.am b/Makefile.am
index ae4e6c8..bb72285 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -158,8 +158,7 @@ TESTS = \
   tests/database.scm \
   tests/http.scm \
   tests/metrics.scm \
-  tests/remote.scm \
-  tests/utils.scm
+  tests/remote.scm
 
 # Compiler warning flags.
 GUILE_WARNINGS =					\
diff --git a/src/cuirass/utils.scm b/src/cuirass/utils.scm
index e087050..45f8f1e 100644
--- a/src/cuirass/utils.scm
+++ b/src/cuirass/utils.scm
@@ -27,13 +27,9 @@
   #:use-module (system foreign)
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-19)
-  #:use-module (json)
   #:use-module (fibers)
   #:use-module (fibers channels)
-  #:export (alist?
-            object->json-scm
-            object->json-string
-            define-enumeration
+  #:export (define-enumeration
 
             make-resource-pool
             with-resource-from-pool
@@ -46,30 +42,6 @@
             random-string
             call-with-time))
 
-(define (alist? obj)
-  "Return #t if OBJ is an alist."
-  (and (list? obj)
-       (every pair? obj)))
-
-(define (object->json-scm obj)
-  "Prepare OBJ for JSON usage."
-  (cond ((string? obj)  obj)
-        ((number? obj)  obj)
-        ((boolean? obj) obj)
-        ((null? obj)    obj)
-        ((symbol? obj)  (symbol->string obj))
-        ((keyword? obj) (object->json-scm (keyword->symbol obj)))
-        ((vector? obj)  (list->vector
-                         (map object->json-scm (vector->list obj))))
-        ((alist? obj)   (map object->json-scm obj))
-        ((pair? obj)    (cons (object->json-scm (car obj))
-                              (object->json-scm (cdr obj))))
-        (else           (object->string obj))))
-
-(define* (object->json-string object #:key pretty)
-  "Return OBJECT as a JSON object."
-  (scm->json-string (object->json-scm object) #:pretty pretty))
-
 (define-syntax-rule (define-enumeration name (symbol value) ...)
   "Define an 'enum' type with the given SYMBOL/VALUE pairs.  NAME is defined a
 macro that accepts one of these symbols and expands to the corresponding
diff --git a/tests/http.scm b/tests/http.scm
index 3bf52d2..fdb0f8a 100644
--- a/tests/http.scm
+++ b/tests/http.scm
@@ -83,27 +83,6 @@
                      (directory . "dir3")))))))
 
 (test-group-with-cleanup "http"
-  (test-assert "object->json-string"
-    (lset= equal?
-           (call-with-input-string
-               (string-append "{"
-                              "\"boolean\" : false,"
-                              "\"string\" : \"guix\","
-                              "\"alist\" : {\"subset\" : \"hello\"},"
-                              "\"list\" : [1, \"2\", \"three\"],"
-                              "\"symbol\" : \"hydra-jobs\","
-                              "\"number\" : 1"
-                              "}")
-             json->scm)
-           (call-with-input-string
-               (object->json-string '((#:number . 1)
-                                      (string . "guix")
-                                      ("symbol" . hydra-jobs)
-                                      (#:alist . ((subset . "hello")))
-                                      (list . #(1 "2" #:three))
-                                      ("boolean" . #f)))
-             json->scm)))
-
   (test-assert "db-init"
     (begin
       (test-init-db!)
diff --git a/tests/utils.scm b/tests/utils.scm
deleted file mode 100644
index d5298c5..0000000
--- a/tests/utils.scm
+++ /dev/null
@@ -1,38 +0,0 @@
-;;;; utils.scm -- tests for (cuirass utils) module
-;;;
-;;; Copyright © 2016 Mathieu Lirzin <mthl@gnu.org>
-;;;
-;;; This file is part of Cuirass.
-;;;
-;;; Cuirass is free software; you can redistribute it and/or modify it
-;;; under the terms of the GNU General Public License as published by
-;;; the Free Software Foundation; either version 3 of the License, or (at
-;;; your option) any later version.
-;;;
-;;; Cuirass is distributed in the hope that it will be useful, but
-;;; WITHOUT ANY WARRANTY; without even the implied warranty of
-;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-;;; GNU General Public License for more details.
-;;;
-;;; You should have received a copy of the GNU General Public License
-;;; along with Cuirass.  If not, see <http://www.gnu.org/licenses/>.
-
-(use-modules (cuirass utils)
-             (srfi srfi-64))
-
-(define dir-1 (make-parameter ""))
-(define dir-2 (make-parameter ""))
-
-(test-begin "utils")
-
-(test-assert "alist?"
-  (and (alist? '())
-       (alist? '(("foo" 1 2)))
-       (alist? '(("foo" . 1)
-                 ("bar" . 2)))
-       (not (alist? 3))
-       (not (alist? '(1 2 3)))
-       (not (alist? 'foo))
-       (not (alist? #:bar))))
-
-(test-end)