diff --git a/src/main/java/org/mitre/synthea/helpers/RandomCodeGenerator.java b/src/main/java/org/mitre/synthea/helpers/RandomCodeGenerator.java
index 35b1f83e5..c77856f59 100644
--- a/src/main/java/org/mitre/synthea/helpers/RandomCodeGenerator.java
+++ b/src/main/java/org/mitre/synthea/helpers/RandomCodeGenerator.java
@@ -110,7 +110,7 @@ private static synchronized void expandValueSet(String valueSetUri) {
     if (!codeListCache.containsKey(valueSetUri)) {
       Request request = new Request.Builder()
               .url(expandBaseUrl + valueSetUri)
-              .header("Content-Type", "application/json")
+              .header("Accept", "application/json")
               .build();
       try {
         Response response = client.newCall(request).execute();