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 74a596b0b..b225d9fff 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
@@ -1500,26 +1500,39 @@ public abstract class BaseWorkerContext extends I18nBase implements IWorkerConte
     for (CanonicalType c : inc.getValueSet()) {
       ValueSet vs = fetchResource(ValueSet.class, c.getValue(), src);
       if (vs != null && !hasCanonicalResource(pin, "tx-resource", vs.getVUrl())) {
-        pin.addParameter().setName("tx-resource").setResource(vs);
-        if (tcc.isTxCaching() && tcc.getCacheId() == null || !tcc.getCached().contains(vs.getVUrl())) {
-          tcc.getCached().add(vs.getVUrl());
-          cache = true;
-        }
+        cache = checkAddToParams(pin, vs) || cache;
         addDependentResources(pin, vs);
       }
     }
     CodeSystem cs = fetchResource(CodeSystem.class, inc.getSystem(), src);
     if (cs != null && !hasCanonicalResource(pin, "tx-resource", cs.getVUrl()) && (cs.getContent() == CodeSystemContentMode.COMPLETE || cs.getContent() == CodeSystemContentMode.FRAGMENT)) {
-      pin.addParameter().setName("tx-resource").setResource(cs);
-      if (tcc.isTxCaching() && tcc.getCacheId() == null || !tcc.getCached().contains(cs.getVUrl())) {
-        tcc.getCached().add(cs.getVUrl());
-        cache = true;
-      }
+      cache = checkAddToParams(pin, cs) || cache;
       // todo: supplements
     }
     return cache;
   }
 
+  private boolean checkAddToParams(Parameters pin, CanonicalResource cr) {
+    boolean cache = false;
+    boolean addToParams = false;
+    if (tcc.usingCache()) {
+      if (!tcc.alreadyCached(cr)) {
+        tcc.addToCache(cr);
+        System.out.println("add to cache: "+cr.getVUrl());
+        addToParams = true;
+        cache = true;
+      } else {
+        System.out.println("already cached: "+cr.getVUrl());
+      }
+    } else {
+      addToParams = true;
+    }
+    if (addToParams) {
+      pin.addParameter().setName("tx-resource").setResource(cr);
+    }
+    return cache;
+  }
+
   private boolean hasCanonicalResource(Parameters pin, String name, String vUrl) {
     for (ParametersParameterComponent p : pin.getParameter()) {
       if (name.equals(p.getName()) && p.hasResource() &&
diff --git a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/terminologies/client/TerminologyClientContext.java b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/terminologies/client/TerminologyClientContext.java
index 9133fe9be..14154562c 100644
--- a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/terminologies/client/TerminologyClientContext.java
+++ b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/terminologies/client/TerminologyClientContext.java
@@ -3,7 +3,9 @@ package org.hl7.fhir.r5.terminologies.client;
 import java.util.HashSet;
 import java.util.Set;
 
+import org.hl7.fhir.r5.model.CanonicalResource;
 import org.hl7.fhir.r5.model.TerminologyCapabilities;
+import org.hl7.fhir.r5.model.ValueSet;
 
 public class TerminologyClientContext {
   private String cacheId;
@@ -76,6 +78,18 @@ public class TerminologyClientContext {
 
   }
 
+  public boolean usingCache() {
+    return isTxCaching && cacheId != null;
+  }
+
+  public boolean alreadyCached(CanonicalResource cr) {
+    return cached.contains(cr.getVUrl());
+  }
+
+  public void addToCache(CanonicalResource cr) {
+    cached.add(cr.getVUrl());
+  }
+
   
   
 }