diff --git a/hapi-fhir-base/src/main/java/org/hl7/fhir/instance/model/api/IBaseEnumFactory.java b/hapi-fhir-base/src/main/java/org/hl7/fhir/instance/model/api/IBaseEnumFactory.java
index 15d05589691..9e2d198dfd4 100644
--- a/hapi-fhir-base/src/main/java/org/hl7/fhir/instance/model/api/IBaseEnumFactory.java
+++ b/hapi-fhir-base/src/main/java/org/hl7/fhir/instance/model/api/IBaseEnumFactory.java
@@ -24,21 +24,26 @@ import java.io.Serializable;
 
 public interface IBaseEnumFactory<T extends Enum<?>> extends Serializable {
 
-    /**
-     * Read an enumeration value from the string that represents it on the XML or JSON
-     *
-     * @param codeString the value found in the XML or JSON
-     * @return the enumeration value
-     * @throws IllegalArgumentException is the value is not known
-     */
-    public T fromCode(String codeString) throws IllegalArgumentException;
+	/**
+	 * Read an enumeration value from the string that represents it on the XML or JSON
+	 *
+	 * @param codeString the value found in the XML or JSON
+	 * @return the enumeration value
+	 * @throws IllegalArgumentException is the value is not known
+	 */
+	T fromCode(String codeString) throws IllegalArgumentException;
 
-    /**
-     * Get the XML/JSON representation for an enumerated value
-     *
-     * @param code - the enumeration value
-     * @return the XML/JSON representation
-     */
-    public String toCode(T code);
+	/**
+	 * Get the XML/JSON representation for an enumerated value
+	 *
+	 * @param code - the enumeration value
+	 * @return the XML/JSON representation
+	 */
+	String toCode(T code);
+
+	/**
+	 * Get the system for a given enum value
+	 */
+	default String toSystem(T theValue) { return null; }
 
 }
diff --git a/hapi-fhir-base/src/main/java/org/hl7/fhir/instance/model/api/IBaseEnumeration.java b/hapi-fhir-base/src/main/java/org/hl7/fhir/instance/model/api/IBaseEnumeration.java
index 13f2a63218b..9f8c2125438 100644
--- a/hapi-fhir-base/src/main/java/org/hl7/fhir/instance/model/api/IBaseEnumeration.java
+++ b/hapi-fhir-base/src/main/java/org/hl7/fhir/instance/model/api/IBaseEnumeration.java
@@ -23,6 +23,6 @@ package org.hl7.fhir.instance.model.api;
 
 public interface IBaseEnumeration<T extends Enum<?>> extends IPrimitiveType<T> {
 
-	// Marker interface
-	
+	default IBaseEnumFactory<T> getEnumFactory() { return null; }
+
 }