diff --git a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/model/ExpressionNode.java b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/model/ExpressionNode.java
index 5330ca00b..65bfd18c6 100644
--- a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/model/ExpressionNode.java
+++ b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/model/ExpressionNode.java
@@ -423,12 +423,18 @@ public class ExpressionNode {
       } else if (constant instanceof StringType) {
         b.append("'" + Utilities.escapeJson(constant.primitiveValue()) + "'");
       } else if (constant instanceof Quantity) {
-		    Quantity q = (Quantity) constant;
+        Quantity q = (Quantity) constant;
         b.append(Utilities.escapeJson(q.getValue().toPlainString()));
-        b.append(" '");
-        b.append(Utilities.escapeJson(q.getUnit()));
-        b.append("'");
-		  } else if (constant.primitiveValue() != null) {
+        if (q.hasUnit() || q.hasCode()) {
+          b.append(" '");
+          if (q.hasUnit()) {
+            b.append(Utilities.escapeJson(q.getUnit()));
+          } else {
+            b.append(Utilities.escapeJson(q.getCode()));
+          }
+          b.append("'");
+        }
+      } else if (constant.primitiveValue() != null) {
         b.append(Utilities.escapeJson(constant.primitiveValue()));
       } else {
         b.append(Utilities.escapeJson(constant.toString()));