diff --git a/modelql-client/src/jvmTest/kotlin/org/modelix/modelql/client/ModelQLClientTest.kt b/modelql-client/src/jvmTest/kotlin/org/modelix/modelql/client/ModelQLClientTest.kt
index 3f2b91cf96..ba5f84b817 100644
--- a/modelql-client/src/jvmTest/kotlin/org/modelix/modelql/client/ModelQLClientTest.kt
+++ b/modelql-client/src/jvmTest/kotlin/org/modelix/modelql/client/ModelQLClientTest.kt
@@ -17,6 +17,7 @@ import io.ktor.client.HttpClient
 import io.ktor.server.routing.routing
 import io.ktor.server.testing.testApplication
 import kotlinx.coroutines.withTimeout
+import org.modelix.model.api.ConceptReference
 import org.modelix.model.api.IConceptReference
 import org.modelix.model.api.INode
 import org.modelix.model.api.PBranch
@@ -43,6 +44,7 @@ import org.modelix.modelql.server.ModelQLServer
 import org.modelix.modelql.untyped.addNewChild
 import org.modelix.modelql.untyped.allChildren
 import org.modelix.modelql.untyped.allReferences
+import org.modelix.modelql.untyped.asMono
 import org.modelix.modelql.untyped.children
 import org.modelix.modelql.untyped.descendants
 import org.modelix.modelql.untyped.nodeReference
@@ -250,4 +252,12 @@ class ModelQLClientTest {
 
         assertEquals(null, nullNode)
     }
+
+    @Test
+    fun `mono can be created from set of concept references`() = runTest { httpClient ->
+        val client = ModelQLClient("http://localhost/query", httpClient)
+        val refSet = setOf(ConceptReference("abc"), ConceptReference("def"))
+        val result = client.query { refSet.asMono() }
+        assertEquals(refSet, result)
+    }
 }
diff --git a/modelql-untyped/src/commonMain/kotlin/org/modelix/modelql/untyped/ConceptReferenceSetSourceStep.kt b/modelql-untyped/src/commonMain/kotlin/org/modelix/modelql/untyped/ConceptReferenceSetSourceStep.kt
new file mode 100644
index 0000000000..f3a86c4843
--- /dev/null
+++ b/modelql-untyped/src/commonMain/kotlin/org/modelix/modelql/untyped/ConceptReferenceSetSourceStep.kt
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2024.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.modelix.modelql.untyped
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+import org.modelix.model.api.ConceptReference
+import org.modelix.modelql.core.ConstantSourceStep
+import org.modelix.modelql.core.IStep
+import org.modelix.modelql.core.QueryDeserializationContext
+import org.modelix.modelql.core.QueryGraphDescriptorBuilder
+import org.modelix.modelql.core.StepDescriptor
+import kotlin.reflect.typeOf
+
+class ConceptReferenceSetSourceStep(val referenceSet: Set<ConceptReference>) : ConstantSourceStep<Set<ConceptReference>>(referenceSet, typeOf<Set<ConceptReference>>()) {
+    override fun createDescriptor(context: QueryGraphDescriptorBuilder): StepDescriptor = Descriptor(referenceSet)
+
+    @Serializable
+    @SerialName("conceptReferenceSetMonoSource")
+    class Descriptor(val referenceSet: Set<ConceptReference>) : StepDescriptor() {
+        override fun createStep(context: QueryDeserializationContext): IStep {
+            return ConceptReferenceSetSourceStep(referenceSet)
+        }
+    }
+
+    override fun canEvaluateStatically(): Boolean = true
+    override fun evaluateStatically(): Set<ConceptReference> = referenceSet
+}
+
+fun Set<ConceptReference>.asMono() = ConceptReferenceSetSourceStep(this)
diff --git a/modelql-untyped/src/commonMain/kotlin/org/modelix/modelql/untyped/UntypedModelQL.kt b/modelql-untyped/src/commonMain/kotlin/org/modelix/modelql/untyped/UntypedModelQL.kt
index 586155a732..5d5eec2bdf 100644
--- a/modelql-untyped/src/commonMain/kotlin/org/modelix/modelql/untyped/UntypedModelQL.kt
+++ b/modelql-untyped/src/commonMain/kotlin/org/modelix/modelql/untyped/UntypedModelQL.kt
@@ -37,6 +37,7 @@ object UntypedModelQL {
             subclass(AllReferencesTraversalStep.Descriptor::class)
             subclass(ChildrenTraversalStep.ChildrenStepDescriptor::class)
             subclass(ConceptReferenceTraversalStep.Descriptor::class)
+            subclass(ConceptReferenceSetSourceStep.Descriptor::class)
             subclass(ConceptReferenceUIDTraversalStep.Descriptor::class)
             subclass(DescendantsTraversalStep.WithSelfDescriptor::class)
             subclass(DescendantsTraversalStep.WithoutSelfDescriptor::class)