diff --git a/ontopy/utils.py b/ontopy/utils.py
index 2a9248e8..b9bfdc92 100644
--- a/ontopy/utils.py
+++ b/ontopy/utils.py
@@ -780,15 +780,25 @@ def rename_iris(onto, annotation="prefLabel"):
     to the value of the annotation.  Also add an `skos:exactMatch`
     annotation referring to the old IRI.
     """
-    exactMatch = onto._abbreviate(  # pylint:disable=invalid-name
-        "http://www.w3.org/2004/02/skos/core#exactMatch"
-    )
+    # exactMatch = onto._abbreviate(  # pylint:disable=invalid-name
+    #     "http://www.w3.org/2004/02/skos/core#exactMatch"
+    # )
     for entity in onto.get_entities():
-        if hasattr(entity, annotation) and getattr(entity, annotation):
-            onto._add_data_triple_spod(
-                entity.storid, exactMatch, entity.iri, ""
-            )
-            entity.name = getattr(entity, annotation).first()
+        label = getattr(entity, annotation).first()
+        if (
+            label
+            and not onto.world[f"{onto.base_iri}{label}"]
+            and hasattr(entity, annotation)
+            and getattr(entity, annotation)
+        ):
+            # pylint: disable=fixme
+            # FIXME: Saving the below skos:exactMatch relations makes Owlready2
+            # crash when saving.
+            #
+            # onto._add_data_triple_spod(
+            #     entity.storid, exactMatch, entity.iri, ""
+            # )
+            entity.name = label
 
 
 def normalise_url(url):
diff --git a/tests/ontopy_tests/test_utils.py b/tests/ontopy_tests/test_utils.py
index 38cf2826..0386bc71 100644
--- a/tests/ontopy_tests/test_utils.py
+++ b/tests/ontopy_tests/test_utils.py
@@ -1,4 +1,10 @@
+import sys
+from pathlib import Path
+
 import ontopy.utils as utils
+
+thisdir = Path(__file__).resolve().parent
+sys.path.append(str(thisdir.parent / "utilities"))
 from utilities import get_triples, has_triple
 
 
@@ -27,16 +33,22 @@ def test_annotate_source(testonto: "Ontology"):
     )
 
 
+# if True:
+#     from ontopy import get_ontology
+#     path = Path(__file__).parent.parent.resolve() / "testonto"
+#     testonto = get_ontology(str(path) + "/testonto.ttl").load()
+
+
 def test_rename_iris(testonto: "Ontology"):
-    assert not has_triple(testonto, s="http://emmo.info/models#TestClass")
+    assert not has_triple(testonto, s="http://emmo.info/testonto#TestClass")
     utils.rename_iris(testonto)
-    assert has_triple(testonto, s="http://emmo.info/models#TestClass")
-    assert has_triple(
-        testonto,
-        "http://emmo.info/models#TestClass",
-        "http://www.w3.org/2004/02/skos/core#exactMatch",
-        "http://emmo.info/models#testclass",
-    )
+    assert has_triple(testonto, s="http://emmo.info/testonto#TestClass")
+    # assert has_triple(
+    #     testonto,
+    #     "http://emmo.info/models#TestClass",
+    #     "http://www.w3.org/2004/02/skos/core#exactMatch",
+    #     "http://emmo.info/models#testclass",
+    # )
 
 
 def test_preferred_language():