diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/examples/ExampleGenerator.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/examples/ExampleGenerator.java
index 2a62a8cae1a2..6471d7f0f051 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/examples/ExampleGenerator.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/examples/ExampleGenerator.java
@@ -171,7 +171,7 @@ public class ExampleGenerator {
                         output.add(kv);
                     }
                 } else {
-                    kv.put(EXAMPLE, null);
+                    kv.put(EXAMPLE, "null");
                     output.add(kv);
                 }
             }