diff --git a/jsonschema/_utils.py b/jsonschema/_utils.py
index ceb880198..9d7f281e2 100644
--- a/jsonschema/_utils.py
+++ b/jsonschema/_utils.py
@@ -1,4 +1,3 @@
-import itertools
 import json
 import pkgutil
 import re
@@ -175,38 +174,29 @@ def equal(one, two):
 def unbool(element, true=object(), false=object()):
     """
     A hack to make True and 1 and False and 0 unique for ``uniq``.
+
+    Recurses through an arbitrarily deep object and unique-ifies True/1 and
+    False/0. Also converts arrays/objects into immutable/hashable alternatives.
+    We have to copy the items anyway to avoid unexpected mutations, so we might
+    as well make the imminent equality check simpler.
     """
 
     if element is True:
         return true
     elif element is False:
         return false
+    elif isinstance(element, list) or isinstance(element, tuple):
+        return tuple(map(unbool, element))
+    elif isinstance(element, dict):
+        # Convert dicts to frozensets of 2-tuples. For equality checks, that's
+        # a reasonable hashable alternative to dicts.
+        return frozenset(map(unbool, element.items()))
     return element
 
 
 def uniq(container):
     """
     Check if all of a container's elements are unique.
-
-    Successively tries first to rely that the elements are hashable, then
-    falls back on them being sortable, and finally falls back on brute
-    force.
     """
 
-    try:
-        return len(set(unbool(i) for i in container)) == len(container)
-    except TypeError:
-        try:
-            sort = sorted(unbool(i) for i in container)
-            sliced = itertools.islice(sort, 1, None)
-            for i, j in zip(sort, sliced):
-                if i == j:
-                    return False
-        except (NotImplementedError, TypeError):
-            seen = []
-            for e in container:
-                e = unbool(e)
-                if e in seen:
-                    return False
-                seen.append(e)
-    return True
+    return len(set(unbool(i) for i in container)) == len(container)
diff --git a/jsonschema/tests/test_jsonschema_test_suite.py b/jsonschema/tests/test_jsonschema_test_suite.py
index c978391f1..3bf277c1a 100644
--- a/jsonschema/tests/test_jsonschema_test_suite.py
+++ b/jsonschema/tests/test_jsonschema_test_suite.py
@@ -87,26 +87,6 @@ def narrow_unicode_build(test):  # pragma: no cover
             subject="host-name",
             description="ends with hyphen",
         )(test)
-        or skip(
-            message=bug(686),
-            subject="uniqueItems",
-            description="[0] and [false] are unique",
-        )(test)
-        or skip(
-            message=bug(686),
-            subject="uniqueItems",
-            description="[1] and [true] are unique",
-        )(test)
-        or skip(
-            message=bug(686),
-            subject="uniqueItems",
-            description="nested [0] and [false] are unique",
-        )(test)
-        or skip(
-            message=bug(686),
-            subject="uniqueItems",
-            description="nested [1] and [true] are unique",
-        )(test)
     ),
 )
 
@@ -161,26 +141,6 @@ def narrow_unicode_build(test):  # pragma: no cover
             subject="hostname",
             description="ends with hyphen",
         )(test)
-        or skip(
-            message=bug(686),
-            subject="uniqueItems",
-            description="[0] and [false] are unique",
-        )(test)
-        or skip(
-            message=bug(686),
-            subject="uniqueItems",
-            description="[1] and [true] are unique",
-        )(test)
-        or skip(
-            message=bug(686),
-            subject="uniqueItems",
-            description="nested [0] and [false] are unique",
-        )(test)
-        or skip(
-            message=bug(686),
-            subject="uniqueItems",
-            description="nested [1] and [true] are unique",
-        )(test)
     ),
 )
 
@@ -234,26 +194,6 @@ def narrow_unicode_build(test):  # pragma: no cover
             subject="hostname",
             description="ends with hyphen",
         )(test)
-        or skip(
-            message=bug(686),
-            subject="uniqueItems",
-            description="[0] and [false] are unique",
-        )(test)
-        or skip(
-            message=bug(686),
-            subject="uniqueItems",
-            description="[1] and [true] are unique",
-        )(test)
-        or skip(
-            message=bug(686),
-            subject="uniqueItems",
-            description="nested [0] and [false] are unique",
-        )(test)
-        or skip(
-            message=bug(686),
-            subject="uniqueItems",
-            description="nested [1] and [true] are unique",
-        )(test)
     ),
 )
 
@@ -327,26 +267,6 @@ def narrow_unicode_build(test):  # pragma: no cover
                 "validation of binary-encoded media type documents"
             ),
         )(test)
-        or skip(
-            message=bug(686),
-            subject="uniqueItems",
-            description="[0] and [false] are unique",
-        )(test)
-        or skip(
-            message=bug(686),
-            subject="uniqueItems",
-            description="[1] and [true] are unique",
-        )(test)
-        or skip(
-            message=bug(686),
-            subject="uniqueItems",
-            description="nested [0] and [false] are unique",
-        )(test)
-        or skip(
-            message=bug(686),
-            subject="uniqueItems",
-            description="nested [1] and [true] are unique",
-        )(test)
     ),
 )