diff --git a/org.hl7.fhir.publisher.core/src/main/java/org/hl7/fhir/igtools/publisher/loaders/AdjunctFileLoader.java b/org.hl7.fhir.publisher.core/src/main/java/org/hl7/fhir/igtools/publisher/loaders/AdjunctFileLoader.java
index c17b6f32..27936473 100644
--- a/org.hl7.fhir.publisher.core/src/main/java/org/hl7/fhir/igtools/publisher/loaders/AdjunctFileLoader.java
+++ b/org.hl7.fhir.publisher.core/src/main/java/org/hl7/fhir/igtools/publisher/loaders/AdjunctFileLoader.java
@@ -214,6 +214,16 @@ private String determineContentType(String ext) {
       return "image/jpeg";
     } else if ("cql".equals(ext)) {
       return "text/cql";
+    } else if ("feature".equals(ext)) {
+      return "text/x-gherkin";
+    } else if ("json".equals(ext)) {
+      return "application/json";
+    } else if ("xml".equals(ext)) {
+      return "application/xml";
+    } else if ("text".equals(ext)) {
+      return "text/plain";
+    } else if ("txt".equals(ext)) {
+      return "text/plain";
     } else {
       return null;
     }