diff --git a/src/cowl_object.c b/src/cowl_object.c
index 2e03cbd..ba7ca94 100644
--- a/src/cowl_object.c
+++ b/src/cowl_object.c
@@ -327,7 +327,6 @@ bool cowl_equals(CowlAny *lhs, CowlAny *rhs) {
             case COWL_OT_VECTOR: return cowl_vector_equals(lhs, rhs);
             case COWL_OT_TABLE: return cowl_table_equals(lhs, rhs);
             case COWL_OT_LITERAL: return cowl_literal_equals(lhs, rhs);
-            case COWL_OT_ONTOLOGY: return cowl_ontology_equals(lhs, rhs);
             default: return lhs == rhs;
         }
     }
@@ -369,7 +368,6 @@ ulib_uint cowl_hash(CowlAny *object) {
             case COWL_OT_VECTOR: return cowl_vector_hash(object);
             case COWL_OT_TABLE: return cowl_table_hash(object);
             case COWL_OT_LITERAL: return cowl_literal_hash(object);
-            case COWL_OT_ONTOLOGY: return cowl_ontology_hash(object);
             default: return ulib_hash_alloc_ptr(object);
         }
     }
diff --git a/src/cowl_ontology.c b/src/cowl_ontology.c
index e2c50c1..b92421b 100644
--- a/src/cowl_ontology.c
+++ b/src/cowl_ontology.c
@@ -151,19 +151,6 @@ CowlVector *cowl_ontology_get_annot(CowlOntology *onto) {
     return onto->annot ? onto->annot : (onto->annot = cowl_vector_ordered_empty());
 }
 
-bool cowl_ontology_equals(CowlOntology *lhs, CowlOntology *rhs) {
-    if (lhs == rhs) return true;
-    if (!(lhs->iri || rhs->iri)) return false;
-    return lhs->iri == rhs->iri && lhs->version == rhs->version;
-}
-
-ulib_uint cowl_ontology_hash(CowlOntology *onto) {
-    if (!onto->iri) return 0;
-    ulib_uint hash = cowl_primitive_hash(onto->iri);
-    if (onto->version) hash = ulib_hash_combine(hash, cowl_primitive_hash(onto->version));
-    return hash;
-}
-
 ulib_uint cowl_ontology_axiom_count(CowlOntology *onto, bool imports) {
     ulib_uint count = 0;
 
diff --git a/src/cowl_ontology_private.h b/src/cowl_ontology_private.h
index 48419d6..d4c12e2 100644
--- a/src/cowl_ontology_private.h
+++ b/src/cowl_ontology_private.h
@@ -41,8 +41,6 @@ struct CowlOntology {
 CowlOntology *cowl_ontology(CowlManager *manager);
 void cowl_ontology_free(CowlOntology *onto);
 cowl_ret cowl_ontology_finalize(CowlOntology *onto);
-COWL_PURE bool cowl_ontology_equals(CowlOntology *lhs, CowlOntology *rhs);
-COWL_PURE ulib_uint cowl_ontology_hash(CowlOntology *onto);
 
 COWL_END_DECLS
 
diff --git a/test/tests/cowl_manager_tests.c b/test/tests/cowl_manager_tests.c
index 3dc842f..a30bd8f 100644
--- a/test/tests/cowl_manager_tests.c
+++ b/test/tests/cowl_manager_tests.c
@@ -125,7 +125,8 @@ static bool cowl_test_manager_write_ontology_path(UString path) {
     utest_assert_not_null(onto_out);
 
     // Check that the written ontology is syntactically equal to the test ontology.
-    cowl_assert_equal(ontology, onto_in, onto_out);
+    utest_assert_ptr(cowl_ontology_get_iri(onto_in), ==, cowl_ontology_get_iri(onto_out));
+    utest_assert_ptr(cowl_ontology_get_version(onto_in), ==, cowl_ontology_get_version(onto_out));
 
     UVec(CowlObjectPtr) imports_in = uvec(CowlObjectPtr);
     CowlIterator iter = cowl_iterator_vec(&imports_in, false);