diff --git a/server/implementation/src/main/java/io/smallrye/graphql/execution/error/ExecutionErrorsService.java b/server/implementation/src/main/java/io/smallrye/graphql/execution/error/ExecutionErrorsService.java
index 5e5700032..c95cf873e 100644
--- a/server/implementation/src/main/java/io/smallrye/graphql/execution/error/ExecutionErrorsService.java
+++ b/server/implementation/src/main/java/io/smallrye/graphql/execution/error/ExecutionErrorsService.java
@@ -132,9 +132,7 @@ private void addKeyValue(JsonObjectBuilder objectBuilder, String key, String val
     }
 
     private void addKeyValue(JsonObjectBuilder objectBuilder, String key, JsonValue value) {
-        if (value == null) {
-            return;
-        }
+        value = value != null ? value : JsonValue.NULL;
         if (config.getErrorExtensionFields().isPresent()) {
             List<String> fieldsThatShouldBeIncluded = config.getErrorExtensionFields().get();
             if (fieldsThatShouldBeIncluded.contains(key)) {