diff --git a/hapi-fhir-validation/src/main/java/org/hl7/fhir/dstu3/hapi/validation/ValidationSupportChain.java b/hapi-fhir-validation/src/main/java/org/hl7/fhir/dstu3/hapi/validation/ValidationSupportChain.java
index 1d7fb84585b7..c3480afd6b8b 100644
--- a/hapi-fhir-validation/src/main/java/org/hl7/fhir/dstu3/hapi/validation/ValidationSupportChain.java
+++ b/hapi-fhir-validation/src/main/java/org/hl7/fhir/dstu3/hapi/validation/ValidationSupportChain.java
@@ -94,9 +94,11 @@ public List<StructureDefinition> fetchAllStructureDefinitions(FhirContext theCon
 	@Override
 	public CodeSystem fetchCodeSystem(FhirContext theCtx, String theSystem) {
 		for (IValidationSupport next : myChain) {
-			CodeSystem retVal = next.fetchCodeSystem(theCtx, theSystem);
-			if (retVal != null) {
-				return retVal;
+			if (next.isCodeSystemSupported(theCtx, theSystem)) {
+				CodeSystem retVal = next.fetchCodeSystem(theCtx, theSystem);
+				if (retVal != null) {
+					return retVal;
+				}
 			}
 		}
 		return null;
diff --git a/hapi-fhir-validation/src/main/java/org/hl7/fhir/r4/hapi/validation/ValidationSupportChain.java b/hapi-fhir-validation/src/main/java/org/hl7/fhir/r4/hapi/validation/ValidationSupportChain.java
index be28686504c6..549d26f5dfb9 100644
--- a/hapi-fhir-validation/src/main/java/org/hl7/fhir/r4/hapi/validation/ValidationSupportChain.java
+++ b/hapi-fhir-validation/src/main/java/org/hl7/fhir/r4/hapi/validation/ValidationSupportChain.java
@@ -71,11 +71,13 @@ public List<IBaseResource> fetchAllConformanceResources(FhirContext theContext)
   }
 
   @Override
-	public CodeSystem fetchCodeSystem(FhirContext theCtx, String uri) {
+	public CodeSystem fetchCodeSystem(FhirContext theCtx, String theSystem) {
 		for (IValidationSupport next : myChain) {
-			CodeSystem retVal = next.fetchCodeSystem(theCtx, uri);
-			if (retVal != null) {
-				return retVal;
+			if (next.isCodeSystemSupported(theCtx, theSystem)) {
+				CodeSystem retVal = next.fetchCodeSystem(theCtx, theSystem);
+				if (retVal != null) {
+					return retVal;
+				}
 			}
 		}
 		return null;
diff --git a/src/changes/changes.xml b/src/changes/changes.xml
index c3f29c86295c..06d3ba70d7bf 100644
--- a/src/changes/changes.xml
+++ b/src/changes/changes.xml
@@ -198,6 +198,11 @@
 				Fixed "because at least one resource has a reference to this resource" delete error message that mistakingly reported
 				the target instead of the source with the reference.
 			</action>
+			<action type="add">
+				ValidationSupportChain will now call isCodeSystemSupported() on each entry in the chain before
+				calling fetchCodeSystem() in order to reduce the work required by chain entries. Thanks to 
+				Anders Havn for the suggestion!
+			</action>
 		</release>
 		<release version="3.7.0" date="2019-02-06" description="Gale">
 			<action type="add">