diff --git a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/utils/StructureMapUtilities.java b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/utils/StructureMapUtilities.java
index b758af0da9..8b03e4f9ec 100644
--- a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/utils/StructureMapUtilities.java
+++ b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/utils/StructureMapUtilities.java
@@ -1933,7 +1933,7 @@ else if (v.size() != 1)
 	          id = UUID.randomUUID().toString().toLowerCase();
 	          b.setIdBase(id);
 	        }
-	        return new Reference().setReference(b.fhirType()+"/"+id);
+          return new StringType(b.fhirType()+"/"+id);
 	      }
 	    case DATEOP :
 	      throw new Error("Rule \""+ruleId+"\": Transform "+tgt.getTransform().toCode()+" not supported yet");