diff --git a/tests/rng.lisp b/tests/rng.lisp
new file mode 100644
index 0000000000000000000000000000000000000000..ad970ddb0fc6509fa729072d3978c87d10aebf52
--- /dev/null
+++ b/tests/rng.lisp
@@ -0,0 +1,55 @@
+;; Tests for RNG
+
+(defpackage :rng-tests
+  (:use :cl :lisp-unit))
+
+(in-package "RNG-TESTS")
+
+(defun 64-bit-rng-state (rng)
+  (let ((state (kernel::xoro-random-state-state rng)))
+    (flet ((convert (x)
+	     (multiple-value-bind (hi lo)
+		 (kernel:double-float-bits x)
+	       (logior (ash (ldb (byte 32 0) hi) 32)
+		       lo))))
+      (values (convert (aref state 0)) (convert (aref state 1))))))
+
+(defun 64-bit-value (rng)
+  (logior (ash (kernel::xoroshiro-chunk rng) 32)
+	  (kernel::xoroshiro-chunk rng)))
+
+(defvar *test-state*)
+  
+(define-test rng.initial-state
+  (setf *test-state*
+	(kernel::make-xoroshiro-object :state (kernel::init-xoro-state #x12345678)
+				       :rand 0
+				       :cached-p nil))
+  (multiple-value-bind (s0 s1)
+      (64-bit-rng-state *test-state*)
+    (assert-equal #x38f1dc39d1906b6f s0)
+    (assert-equal #xdfe4142236dd9517 s1)
+    (assert-equal 0 (kernel::xoro-random-state-rand *test-state*))
+    (assert-equal nil (kernel::xoro-random-state-cached-p *test-state*))))
+
+
+(define-test rng.values-test
+  (assert-equal (list #x38f1dc39d1906b6f #xdfe4142236dd9517)
+		(multiple-value-list (64-bit-rng-state *test-state*)))
+  (assert-equal 0 (kernel::xoro-random-state-rand *test-state*))
+  (assert-equal nil (kernel::xoro-random-state-cached-p *test-state*))
+
+  (dolist (item '((#x18d5f05c086e0086 (#x228f4926843b364d #x74dfe78e715c81be))
+		  (#x976f30b4f597b80b (#x5b6bd4558bd96a68 #x567b7f35650aea8f))
+		  (#xb1e7538af0e454f7 (#x13e5253e242fac52 #xed380e70d10ab60e))
+		  (#x011d33aef53a6260 (#x9d0764952ca00d8a #x5251a5cfedd2b4ef))
+		  (#xef590a651a72c279 (#xba4ef2b425bda963 #x172b965cf56c15ac))
+		  (#xd17a89111b29bf0f (#x458277a5e5f0a21b #xd1bccfad6564e8d))
+		  (#x529e44a0bc46f0a8 (#x2becb68d5a7194c7 #x3a6ec964899bb5f3))
+		  (#x665b7ff1e40d4aba (#xededfd481d0a19fe #x3ea213411827fe9d))
+		  (#x2c9010893532189b (#xd7bb59bcd8fba26f #x52de763d34fee090))
+		  (#x2a99cffa0dfa82ff (#xf96e892c62d6ff2e #xc0542ff85652f81e))))
+    (destructuring-bind (value state)
+	item
+      (assert-equal value (64-bit-value *test-state*))
+      (assert-equal state (multiple-value-list (64-bit-rng-state *test-state*))))))