diff --git a/tests/hypothesis/_strategies.py b/tests/hypothesis/_strategies.py
index 34268ae..5a13511 100644
--- a/tests/hypothesis/_strategies.py
+++ b/tests/hypothesis/_strategies.py
@@ -172,15 +172,19 @@ def _bidict_and_mapping_from_items(
     else:
         map_cls = draw(map_types)
     bi_items_ = draw(bi_items)
-    if map_items in (_SAME_AS_BI_ITEMS, _SAME_AS_BI_ITEMS_DIFF_ORDER):
+    same_items = map_items in (_SAME_AS_BI_ITEMS, _SAME_AS_BI_ITEMS_DIFF_ORDER)
+    if same_items:
         map_items_ = bi_items_[:]
         if map_items is _SAME_AS_BI_ITEMS_DIFF_ORDER:
             draw(RAND).shuffle(map_items_)
             assume(map_items_ != bi_items_)
     else:
         map_items_ = draw(map_items)
-        assume(map_items_ != bi_items_)
-    return bi_cls(bi_items_), map_cls(map_items_)
+    b = bi_cls(bi_items_)
+    m = map_cls(map_items_)
+    if not same_items:
+        assume(m.items() != b.items())
+    return b, m
 
 
 BIDICT_AND_MAPPING_FROM_SAME_ITEMS_NODUP = _bidict_and_mapping_from_items()
diff --git a/tests/hypothesis/test_properties.py b/tests/hypothesis/test_properties.py
index 8d14bff..0df0b1e 100644
--- a/tests/hypothesis/test_properties.py
+++ b/tests/hypothesis/test_properties.py
@@ -15,7 +15,7 @@ from collections import OrderedDict
 from weakref import ref
 
 import pytest
-from hypothesis import given
+from hypothesis import HealthCheck, given, settings
 
 import _setup_hypothesis
 import _strategies as st
@@ -43,6 +43,7 @@ def test_unequal_to_non_mapping(bi, not_a_mapping):
 
 
 @given(st.BIDICT_AND_MAPPING_FROM_DIFFERENT_ITEMS)
+@settings(suppress_health_check=[HealthCheck.too_slow])
 def test_unequal_to_mapping_with_different_items(bidict_and_mapping_from_different_items):
     """Bidicts should be unequal to mappings containing different items."""
     bi, mapping = bidict_and_mapping_from_different_items