diff --git a/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsConditionMapper.java b/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsConditionMapper.java
index 3f284e75..4b67a61c 100644
--- a/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsConditionMapper.java
+++ b/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsConditionMapper.java
@@ -157,7 +157,7 @@ public Bundle mapOnkoResourcesToCondition(
 
     onkoCondition.setSubject(
         new Reference()
-            .setReference(ResourceType.Patient + "/" + this.getHash(ResourceType.Patient, pid))
+            .setReference(this.getReference(ResourceType.Patient, pid))
             .setIdentifier(
                 new Identifier()
                     .setSystem(fhirProperties.getSystems().getPatientId())
diff --git a/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsMedicationStatementMapper.java b/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsMedicationStatementMapper.java
index ffa05536..ae1320be 100644
--- a/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsMedicationStatementMapper.java
+++ b/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsMedicationStatementMapper.java
@@ -149,10 +149,7 @@ public MedicationStatement createSystemtherapyMedicationStatement(
         stMedicationStatement.setPartOf(
             List.of(
                 new Reference()
-                    .setReference(
-                        ResourceType.MedicationStatement
-                            + "/"
-                            + this.getHash(ResourceType.MedicationStatement, partOfId))));
+                    .setReference(this.getReference(ResourceType.MedicationStatement, partOfId))));
       }
 
     } else {
diff --git a/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsObservationMapper.java b/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsObservationMapper.java
index efc250cd..b1965b48 100644
--- a/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsObservationMapper.java
+++ b/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsObservationMapper.java
@@ -318,7 +318,7 @@ public Bundle mapOnkoResourcesToObservationsBundle(
 
     var patientReference =
         new Reference()
-            .setReference(ResourceType.Patient + "/" + this.getHash(ResourceType.Patient, patId))
+            .setReference(this.getReference(ResourceType.Patient, patId))
             .setIdentifier(
                 new Identifier()
                     .setSystem(fhirProperties.getSystems().getPatientId())
@@ -556,10 +556,7 @@ public Bundle createHistologieAndGradingObservation(
     if (grading != null) {
       histObs.addHasMember(
           new Reference()
-              .setReference(
-                  ResourceType.Observation
-                      + "/"
-                      + this.getHash(ResourceType.Observation, gradingObsIdentifier)));
+              .setReference(this.getReference(ResourceType.Observation, gradingObsIdentifier)));
     }
 
     bundle = addResourceAsEntryInBundle(bundle, histObs);
diff --git a/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsProcedureMapper.java b/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsProcedureMapper.java
index d8053b33..54b5084c 100644
--- a/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsProcedureMapper.java
+++ b/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsProcedureMapper.java
@@ -167,11 +167,7 @@ public Procedure createOpProcedure(
       if (distinctOpsSet.size() > 1) {
         opProcedure.setPartOf(
             List.of(
-                new Reference()
-                    .setReference(
-                        ResourceType.Procedure
-                            + "/"
-                            + this.getHash(ResourceType.Procedure, partOfId))));
+                new Reference().setReference(this.getReference(ResourceType.Procedure, partOfId))));
       }
 
       // Code
diff --git a/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsToFhirMapper.java b/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsToFhirMapper.java
index a888543e..6e243e3a 100644
--- a/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsToFhirMapper.java
+++ b/src/main/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsToFhirMapper.java
@@ -67,6 +67,10 @@ protected String getHash(ResourceType type, String id) {
     return Hashing.sha256().hashString(idToHash + "|" + id, StandardCharsets.UTF_8).toString();
   }
 
+  protected String getReference(ResourceType type, String id) {
+    return type + "/" + this.getHash(type, id);
+  }
+
   protected String computeResourceIdFromIdentifier(Identifier identifier) {
     return Hashing.sha256()
         .hashString(identifier.getSystem() + "|" + identifier.getValue(), StandardCharsets.UTF_8)
diff --git a/src/test/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsToFhirIntegrationTest.java b/src/test/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsToFhirIntegrationTest.java
index 0ec81312..4c9e82bc 100644
--- a/src/test/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsToFhirIntegrationTest.java
+++ b/src/test/java/org/miracum/streams/ume/obdstofhir/mapper/ObdsToFhirIntegrationTest.java
@@ -1,9 +1,12 @@
 package org.miracum.streams.ume.obdstofhir.mapper;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.doAnswer;
 
+import org.hl7.fhir.r4.model.ResourceType;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.CsvSource;
@@ -17,9 +20,10 @@
 
 @ExtendWith(SpringExtension.class)
 @Import({ObdsTestMapper.class})
-@MockBean(FhirProperties.class)
 public class ObdsToFhirIntegrationTest {
 
+  @MockBean FhirProperties fhirProperties;
+
   ObdsTestMapper mapper;
 
   @BeforeEach
@@ -96,6 +100,26 @@ void applyPatientIdPattern(String input, String output) {
       assertThat(actual).isEqualTo(output);
     }
   }
+
+  @Nested
+  class References {
+
+    @Test
+    void shouldCreateReferenceString() {
+      doAnswer(
+              invocationOnMock -> {
+                final var fhirSystems = new FhirProperties.FhirSystems();
+                fhirSystems.setPatientId("https://fhir.diz.uk-erlangen.de/identifiers/patient-id");
+                return fhirSystems;
+              })
+          .when(fhirProperties)
+          .getSystems();
+
+      final var actual = mapper.getReference(ResourceType.Patient, "1");
+      assertThat(actual)
+          .isEqualTo("Patient/82a86769573e519a1fa2d79911fb19fbdceabe2416a5c9230b503618a23a31c1");
+    }
+  }
 }
 
 @Component