diff --git a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/conformance/ProfileUtilities.java b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/conformance/ProfileUtilities.java
index f258891e8..9e06398cd 100644
--- a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/conformance/ProfileUtilities.java
+++ b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/conformance/ProfileUtilities.java
@@ -3037,8 +3037,8 @@ public class ProfileUtilities extends TranslatingUtilities {
             if (!useTableForFixedValues || definition.getFixed().isPrimitive())
               c.getPieces().add(checkForNoChange(definition.getFixed(), gen.new Piece(null, buildJson(definition.getFixed()), null).addStyle("color: darkgreen")));
             else {
-              c.getPieces().add(checkForNoChange(definition.getPattern(), gen.new Piece(null, "As shown", null).addStyle("color: darkgreen")));
-              genFixedValue(gen, row, definition.getPattern(), snapshot, false, corePath);              
+              c.getPieces().add(checkForNoChange(definition.getFixed(), gen.new Piece(null, "As shown", null).addStyle("color: darkgreen")));
+              genFixedValue(gen, row, definition.getFixed(), snapshot, false, corePath);              
             }
             if (isCoded(definition.getFixed()) && !hasDescription(definition.getFixed())) {
               Piece p = describeCoded(gen, definition.getFixed());
diff --git a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/context/BaseWorkerContext.java b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/context/BaseWorkerContext.java
index e93e5cdd8..beb38579e 100644
--- a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/context/BaseWorkerContext.java
+++ b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/context/BaseWorkerContext.java
@@ -1115,5 +1115,15 @@ public abstract class BaseWorkerContext implements IWorkerContext {
   public void setUcumService(UcumService ucumService) {
     this.ucumService = ucumService;
   }
+
+  @Override
+  public List<StructureDefinition> getStructures() {
+    List<StructureDefinition> res = new ArrayList<>();
+    synchronized (lock) { // tricky, because you need to lock this as well, but it's really not in use yet
+      res.addAll(structures.values());
+    }
+    return res;
+  }
+  
   
 }
diff --git a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/context/IWorkerContext.java b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/context/IWorkerContext.java
index bf4ac47e6..30fb3dfb0 100644
--- a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/context/IWorkerContext.java
+++ b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/context/IWorkerContext.java
@@ -22,9 +22,11 @@ package org.hl7.fhir.r5.context;
 
 
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 
 import org.fhir.ucum.UcumService;
+import org.hl7.fhir.exceptions.DefinitionException;
 import org.hl7.fhir.exceptions.FHIRException;
 import org.hl7.fhir.exceptions.TerminologyServiceException;
 import org.hl7.fhir.r5.formats.IParser;
@@ -210,8 +212,10 @@ public interface IWorkerContext {
   public List<String> getResourceNames();
   public Set<String> getResourceNamesAsSet();
   public List<String> getTypeNames();
-  public List<StructureDefinition> allStructures();
+  public List<StructureDefinition> allStructures(); // ensure snapshot exists...
+  public List<StructureDefinition> getStructures();
   public List<MetadataResource> allConformanceResources();
+  public void generateSnapshot(StructureDefinition p) throws DefinitionException, FHIRException;
   
   // -- Terminology services ------------------------------------------------------
 
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 76d25f40d..c73b65901 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
@@ -117,13 +117,15 @@ public abstract class ParserBase {
       return null;
   	}
     // first pass: only look at base definitions
-	  for (StructureDefinition sd : context.allStructures()) {
+	  for (StructureDefinition sd : context.getStructures()) {
 	    if (sd.getUrl().equals("http://hl7.org/fhir/StructureDefinition/"+name)) {
+	      context.generateSnapshot(sd); 
 	      return sd;
 	    }
 	  }
-    for (StructureDefinition sd : context.allStructures()) {
+    for (StructureDefinition sd : context.getStructures()) {
       if (name.equals(sd.getType()) && sd.getDerivation() == TypeDerivationRule.SPECIALIZATION) {
+        context.generateSnapshot(sd); 
         return sd;
       }
     }