diff --git a/org.hl7.fhir.r4b/src/main/java/org/hl7/fhir/r4b/elementmodel/Property.java b/org.hl7.fhir.r4b/src/main/java/org/hl7/fhir/r4b/elementmodel/Property.java
index dcc77636b..4eb548934 100644
--- a/org.hl7.fhir.r4b/src/main/java/org/hl7/fhir/r4b/elementmodel/Property.java
+++ b/org.hl7.fhir.r4b/src/main/java/org/hl7/fhir/r4b/elementmodel/Property.java
@@ -72,9 +72,9 @@ public class Property {
   }
 
   public String getXmlName() {
-    if (definition.hasExtension("http://hl7.org/fhir/StructureDefinition/elementdefinition-xml-name")) {
+    if (definition.hasExtension(ToolingExtensions.EXT_XML_NAME)) {
       return ToolingExtensions.readStringExtension(definition,
-          "http://hl7.org/fhir/StructureDefinition/elementdefinition-xml-name");
+          ToolingExtensions.EXT_XML_NAME);
     } else {
       return getName();
     }
diff --git a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/elementmodel/ParserBase.java b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/elementmodel/ParserBase.java
index 9b91cee0d..b78b5d7a5 100644
--- a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/elementmodel/ParserBase.java
+++ b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/elementmodel/ParserBase.java
@@ -145,7 +145,7 @@ public abstract class ParserBase {
 	
 	protected StructureDefinition getDefinition(List<ValidationMessage> errors, int line, int col, String ns, String name) throws FHIRFormatError {
 	  if (logical != null) {
-	    String expectedName = ToolingExtensions.readStringExtension(logical, "http://hl7.org/fhir/StructureDefinition/elementdefinition-xml-name");
+	    String expectedName = ToolingExtensions.readStringExtension(logical, ToolingExtensions.EXT_XML_NAME);
 	    if (expectedName == null) {
 	      expectedName = logical.getType();
 	      if (Utilities.isAbsoluteUrl(expectedName)) {