diff --git a/Makefile b/Makefile
index 482e6e7..d79e8d0 100644
--- a/Makefile
+++ b/Makefile
@@ -18,3 +18,9 @@ build:
 	--eval '(ql:quickload :mirror-img/unix)' \
 	--eval '(asdf:make :mirror-img/unix)' \
 	--eval '(quit)'
+
+test:
+	$(LISP) --load mirror-img.asd \
+	--eval '(ql:quickload :mirror-img)' \
+	--eval '(asdf:test-system :mirror-img)' \
+	--eval '(quit)'
diff --git a/mirror-img.asd b/mirror-img.asd
index 3fe8ce2..93051aa 100644
--- a/mirror-img.asd
+++ b/mirror-img.asd
@@ -6,7 +6,8 @@
   :author "Jaidyn Ann <jadedctrl@posteo.at>"
   :depends-on (:dexador :lquery :split-sequence)
   :components ((:file "src/mirror-img"))
-  :in-order-to ((build-op (build-op "mirror-img/unix"))))
+  :in-order-to ((test-op (test-op "mirror-img/tests"))
+                (build-op (build-op "mirror-img/unix"))))
 
 (asdf:defsystem "mirror-img/unix"
   :version "0.1"
@@ -18,3 +19,22 @@
   :entry-point "mirror-img/unix:main"
   :depends-on (:mirror-img :unix-opts :cl-strings)
   :components ((:file "src/unix")))
+
+
+
+;;; Tests
+;;; —————————————————————————————————————
+(asdf:defsystem "mirror-img/tests"
+  :version "0.1"
+  :license "GPLv3"
+  :author "Jaidyn Ann <jadedctrl@posteo.at>"
+  :description "Tests for the the mirror-img package."
+  :depends-on (:mirror-img :lisp-unit2)
+  :components ((:file "t/mirror-img")))
+
+;; Following method borrowed from lisp-unit2’s documentation:
+;; https://github.com/AccelerationNet/lisp-unit2/blob/master/README.md#asdf
+(defmethod asdf:perform ((o asdf:test-op) (c (eql (asdf:find-system :mirror-img/tests))))
+  (eval (read-from-string
+         "(lisp-unit2:with-summary ()
+            (lisp-unit2:run-tests :package :mirror-img/tests))")))
diff --git a/t/mirror-img.lisp b/t/mirror-img.lisp
new file mode 100644
index 0000000..80076a4
--- /dev/null
+++ b/t/mirror-img.lisp
@@ -0,0 +1,36 @@
+;;;; mirror-img/tests: Tests for the mirror-img package.
+
+;; Copyright © 2024 Jaidyn Ann <jadedctrl@posteo.at>
+;;
+;; This program 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.
+;;
+;; This program 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 this program. If not, see <https://www.gnu.org/licenses/>.
+
+(defpackage :mirror-img/tests
+  (:use :cl :lisp-unit2))
+
+(in-package :mirror-img/tests)
+
+(define-test mirrored-pathname (:tags '(base))
+  (assert-equal
+   (mirror-img::mirrored-pathname "https://invalid.tld/dir/bird apple.txt" #p"base/")
+   #p"base/invalid.tld/bird apple.txt"))
+
+(define-test url-encode-uri.space (:tags '(util))
+  (assert-equal
+   (mirror-img::url-encode-uri "https://invalid.tld/dad alive.jpg")
+   "https://invalid.tld/dad%20alive.jpg"))
+
+(define-test url-encode-path.space+exclamation (:tags '(util))
+  (assert-equal
+   (mirror-img::url-encode-path "/images!/dad alive.jpg")
+   "/images%21/dad%20alive.jpg"))