diff --git a/org.hl7.fhir.r4/src/main/java/org/hl7/fhir/r4/context/BaseWorkerContext.java b/org.hl7.fhir.r4/src/main/java/org/hl7/fhir/r4/context/BaseWorkerContext.java
index e2fdf9c86..cee43d1ff 100644
--- a/org.hl7.fhir.r4/src/main/java/org/hl7/fhir/r4/context/BaseWorkerContext.java
+++ b/org.hl7.fhir.r4/src/main/java/org/hl7/fhir/r4/context/BaseWorkerContext.java
@@ -39,6 +39,7 @@ import org.hl7.fhir.r4.conformance.ProfileUtilities;
 import org.hl7.fhir.r4.context.TerminologyCache.CacheToken;
 import org.hl7.fhir.r4.model.BooleanType;
 import org.hl7.fhir.r4.model.CodeSystem;
+import org.hl7.fhir.r4.model.CodeSystem.CodeSystemContentMode;
 import org.hl7.fhir.r4.model.CodeSystem.ConceptDefinitionComponent;
 import org.hl7.fhir.r4.model.CodeableConcept;
 import org.hl7.fhir.r4.model.Coding;
@@ -285,7 +286,7 @@ public abstract class BaseWorkerContext implements IWorkerContext {
   @Override
   public boolean supportsSystem(String system) throws TerminologyServiceException {
     synchronized (lock) {
-      if (codeSystems.containsKey(system))
+      if (codeSystems.containsKey(system) && codeSystems.get(system).getContent() != CodeSystemContentMode.NOTPRESENT)
         return true;
       else if (supportedCodeSystems.contains(system))
         return true;
diff --git a/r4 test resources.lnk b/r4 test resources.lnk
new file mode 100644
index 000000000..9a6787c01
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diff --git a/validation test resources.lnk b/validation test resources.lnk
new file mode 100644
index 000000000..20bb98b08
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