diff --git a/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/txClient/TerminologyClientR2.java b/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/txClient/TerminologyClientR2.java
index 5cbc96328..e6ba510b0 100644
--- a/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/txClient/TerminologyClientR2.java
+++ b/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/txClient/TerminologyClientR2.java
@@ -53,6 +53,7 @@ import org.hl7.fhir.r5.utils.client.network.ClientHeaders;
 import org.hl7.fhir.utilities.FhirPublication;
 import org.hl7.fhir.utilities.ToolingClientLogger;
 import org.hl7.fhir.utilities.Utilities;
+import org.hl7.fhir.utilities.http.HTTPHeader;
 
 public class TerminologyClientR2 implements ITerminologyClient {
 
@@ -211,7 +212,7 @@ public class TerminologyClientR2 implements ITerminologyClient {
   }
 
   @Override
-  public ClientHeaders getClientHeaders() {
+  public Iterable<HTTPHeader> getClientHeaders() {
     return null;
   }
 
diff --git a/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/txClient/TerminologyClientR3.java b/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/txClient/TerminologyClientR3.java
index 84f51cd38..de07084d6 100644
--- a/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/txClient/TerminologyClientR3.java
+++ b/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/txClient/TerminologyClientR3.java
@@ -53,6 +53,7 @@ import org.hl7.fhir.r5.utils.client.network.ClientHeaders;
 import org.hl7.fhir.utilities.FhirPublication;
 import org.hl7.fhir.utilities.ToolingClientLogger;
 import org.hl7.fhir.utilities.Utilities;
+import org.hl7.fhir.utilities.http.HTTPHeader;
 
 public class TerminologyClientR3 implements ITerminologyClient {
 
@@ -201,8 +202,8 @@ public class TerminologyClientR3 implements ITerminologyClient {
   }
 
   @Override
-  public ClientHeaders getClientHeaders() {
-    return clientHeaders;
+  public Iterable<HTTPHeader> getClientHeaders() {
+    return clientHeaders.headers();
   }
 
   @Override
diff --git a/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/txClient/TerminologyClientR4.java b/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/txClient/TerminologyClientR4.java
index 313de8c67..b4aaa69f0 100644
--- a/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/txClient/TerminologyClientR4.java
+++ b/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/txClient/TerminologyClientR4.java
@@ -24,6 +24,7 @@ import org.hl7.fhir.r5.utils.client.network.ClientHeaders;
 import org.hl7.fhir.utilities.FhirPublication;
 import org.hl7.fhir.utilities.ToolingClientLogger;
 import org.hl7.fhir.utilities.Utilities;
+import org.hl7.fhir.utilities.http.HTTPHeader;
 
 public class TerminologyClientR4 implements ITerminologyClient {
 
@@ -226,8 +227,8 @@ public class TerminologyClientR4 implements ITerminologyClient {
   }
 
   @Override
-  public ClientHeaders getClientHeaders() {
-    return clientHeaders;
+  public Iterable<HTTPHeader> getClientHeaders() {
+    return clientHeaders.headers();
   }
 
   @Override
diff --git a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/terminologies/client/ITerminologyClient.java b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/terminologies/client/ITerminologyClient.java
index 172b9349e..fec587dce 100644
--- a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/terminologies/client/ITerminologyClient.java
+++ b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/terminologies/client/ITerminologyClient.java
@@ -36,6 +36,7 @@ import org.hl7.fhir.r5.model.Enumerations.FHIRVersion;
 import org.hl7.fhir.r5.utils.client.network.ClientHeaders;
 import org.hl7.fhir.utilities.FhirPublication;
 import org.hl7.fhir.utilities.ToolingClientLogger;
+import org.hl7.fhir.utilities.http.HTTPHeader;
 
 import java.util.EnumSet;
 import java.util.Map;
@@ -67,7 +68,7 @@ public interface ITerminologyClient {
   Parameters translate(Parameters params) throws FHIRException;
   Bundle validateBatch(Bundle batch);
   CanonicalResource read(String type, String id);
-  ClientHeaders getClientHeaders();
+  Iterable<HTTPHeader> getClientHeaders();
   ITerminologyClient setClientHeaders(ClientHeaders clientHeaders);
   ITerminologyClient setUserAgent(String userAgent);
   ITerminologyClient setAcceptLanguage(String lang);
diff --git a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/terminologies/client/TerminologyClientR5.java b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/terminologies/client/TerminologyClientR5.java
index fd859b0e9..9946c583b 100644
--- a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/terminologies/client/TerminologyClientR5.java
+++ b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/terminologies/client/TerminologyClientR5.java
@@ -49,6 +49,7 @@ import org.hl7.fhir.r5.utils.client.network.ClientHeaders;
 import org.hl7.fhir.utilities.FhirPublication;
 import org.hl7.fhir.utilities.ToolingClientLogger;
 import org.hl7.fhir.utilities.Utilities;
+import org.hl7.fhir.utilities.http.HTTPHeader;
 
 public class TerminologyClientR5 implements ITerminologyClient {
 
@@ -215,8 +216,8 @@ public class TerminologyClientR5 implements ITerminologyClient {
   }
 
   @Override
-  public ClientHeaders getClientHeaders() {
-    return clientHeaders;
+  public Iterable<HTTPHeader> getClientHeaders() {
+    return clientHeaders.headers();
   }
 
   @Override