diff --git a/pkg/arvo/tests/sys/zuse/mimes.hoon b/pkg/arvo/tests/sys/zuse/mimes.hoon
new file mode 100644
index 000000000..57932f693
--- /dev/null
+++ b/pkg/arvo/tests/sys/zuse/mimes.hoon
@@ -0,0 +1,64 @@
+::  tests for |mimes:html
+::
+/+  *test
+=,  mimes:html
+|%
+++  test-en-base16
+  ;:  weld
+    %+  expect-eq
+      !>  'aa'
+      !>  (en:base16 (as-octs 0xaa))
+  ::
+    %+  expect-eq
+      !>  '1234'
+      !>  (en:base16 (as-octs 0x1234))
+  ::
+    %+  expect-eq
+      !>  'f012'
+      !>  (en:base16 (as-octs 0xf012))
+  ::
+    %+  expect-eq
+      !>  '010b'
+      !>  (en:base16 (as-octs 0x10b))
+  ::
+    %+  expect-eq
+      !>  '001234'
+      !>  (en:base16 3 0x1234)
+  ::
+    %+  expect-eq
+      !>  '34'
+      !>  (en:base16 1 0x1234)
+  ==
+::
+++  test-de-base16
+  ;:  weld
+    %+  expect-eq
+      !>  `[1 0xaa]
+      !>  ^-  (unit [@ud @ux])
+          (de:base16 'aa')
+  ::
+    %+  expect-eq
+      !>  `[2 0x1234]
+      !>  `(unit [@ud @ux])`(de:base16 '1234')
+  ::
+    %+  expect-eq
+      !>  `[2 `@`0xf012]
+      !>  ^-  (unit [@ud @ux])
+          (de:base16 'f012')
+  ::
+    %+  expect-eq
+      !>  lz=`[2 0x10b]
+      !>  ^-  (unit [@ud @ux])
+          (de:base16 '010b')
+  ::
+    %+  expect-eq
+      !>  nlz=`[2 0x10b]
+      !>  ^-  (unit [@ud @ux])
+          (de:base16 '10b')
+  ::
+    %+  expect-eq
+      !>  `[3 0x1234]
+      !>  ^-  (unit [@ud @ux])
+          (de:base16 '001234')
+  ==
+--