diff --git a/modules/search-api/src/test/scala/io/renku/search/api/SearchApiSpec.scala b/modules/search-api/src/test/scala/io/renku/search/api/SearchApiSpec.scala
index 84a401f9..975bfa91 100644
--- a/modules/search-api/src/test/scala/io/renku/search/api/SearchApiSpec.scala
+++ b/modules/search-api/src/test/scala/io/renku/search/api/SearchApiSpec.scala
@@ -44,7 +44,7 @@ class SearchApiSpec extends CatsEffectSuite with SearchSolrSuite:
     val project1 = projectDocumentGen(
       "matching",
       "matching description",
-      Gen.const(None),
+      userDocumentGen.asOption,
       Gen.const(None),
       Gen.const(Visibility.Public)
     ).generateOne
@@ -76,7 +76,7 @@ class SearchApiSpec extends CatsEffectSuite with SearchSolrSuite:
     val project = projectDocumentGen(
       "exclusive",
       "exclusive description",
-      Gen.const(None),
+      userDocumentGen.asOption,
       Gen.const(None),
       Gen.const(Visibility.Public)
     ).generateOne.copy(createdBy = userId)
diff --git a/modules/search-solr-client/src/test/scala/io/renku/search/solr/client/SearchSolrClientSpec.scala b/modules/search-solr-client/src/test/scala/io/renku/search/solr/client/SearchSolrClientSpec.scala
index 52075f47..a59ea533 100644
--- a/modules/search-solr-client/src/test/scala/io/renku/search/solr/client/SearchSolrClientSpec.scala
+++ b/modules/search-solr-client/src/test/scala/io/renku/search/solr/client/SearchSolrClientSpec.scala
@@ -43,6 +43,29 @@ class SearchSolrClientSpec extends CatsEffectSuite with SearchSolrSuite:
   override def munitFixtures: Seq[munit.AnyFixture[?]] =
     List(solrServer, searchSolrClient)
 
+  test("ignore entities with non-existing namespace"):
+    val user = userDocumentGen.generateOne
+    val group = groupDocumentGen.generateOne
+    val project0 = projectDocumentGen(
+      "project-test0",
+      "project-test0 description",
+      Gen.const(None),
+      Gen.const(None)
+    ).generateOne.copy(createdBy = user.id, namespace = group.namespace.some)
+    val project1 = projectDocumentGen(
+      "project-test1",
+      "project-test1 description",
+      Gen.const(None),
+      Gen.const(None)
+    ).generateOne.copy(createdBy = user.id, namespace = group.namespace.some)
+
+    for
+      client <- IO(searchSolrClient())
+      _ <- IO.println(client)
+      _ <- IO.println(project0)
+      _ <- IO.println(project1)
+    yield ()
+
   test("load project with resolved namespace and creator"):
     val user = userDocumentGen.generateOne
     val group = groupDocumentGen.generateOne