diff --git a/kubernetes-model-generator/openapi/maven-plugin/src/main/java/io/fabric8/kubernetes/schema/generator/GeneratorSettings.java b/kubernetes-model-generator/openapi/maven-plugin/src/main/java/io/fabric8/kubernetes/schema/generator/GeneratorSettings.java
index 151a7daffc4..8db2311aab8 100644
--- a/kubernetes-model-generator/openapi/maven-plugin/src/main/java/io/fabric8/kubernetes/schema/generator/GeneratorSettings.java
+++ b/kubernetes-model-generator/openapi/maven-plugin/src/main/java/io/fabric8/kubernetes/schema/generator/GeneratorSettings.java
@@ -185,7 +185,9 @@ private static Map<String, ApiVersion> computeApiVersions(OpenAPI openAPI) {
       for (Operation operation : new Operation[] { apiPath.getValue().getGet(), apiPath.getValue().getPost() }) {
         if (operation == null
             || operation.getResponses().get("200") == null
-            || operation.getResponses().get("200").getContent().get(APPLICATION_JSON) == null) {
+            || operation.getResponses().get("200").getContent().get(APPLICATION_JSON) == null
+            || operation.getExtensions() == null
+            || operation.getExtensions().get("x-kubernetes-group-version-kind") == null) {
           continue;
         }
         final ApiVersion.ApiVersionBuilder apiVersionBuilder = ApiVersion.builder();
@@ -196,9 +198,6 @@ private static Map<String, ApiVersion> computeApiVersions(OpenAPI openAPI) {
         //        } else {
         //          apiVersionBuilder.group("").version("v1");
         //        }
-        if (operation.getExtensions() == null || operation.getExtensions().get("x-kubernetes-group-version-kind") == null) {
-          continue;
-        }
         final Map<String, String> groupVersionKind = (Map<String, String>) operation.getExtensions()
             .get("x-kubernetes-group-version-kind");
         apiVersionBuilder.group(groupVersionKind.get("group"));
diff --git a/kubernetes-model-generator/openapi/maven-plugin/src/main/java/io/fabric8/kubernetes/schema/generator/model/ModelGenerator.java b/kubernetes-model-generator/openapi/maven-plugin/src/main/java/io/fabric8/kubernetes/schema/generator/model/ModelGenerator.java
index f55a4d1a602..cbc662f19ba 100644
--- a/kubernetes-model-generator/openapi/maven-plugin/src/main/java/io/fabric8/kubernetes/schema/generator/model/ModelGenerator.java
+++ b/kubernetes-model-generator/openapi/maven-plugin/src/main/java/io/fabric8/kubernetes/schema/generator/model/ModelGenerator.java
@@ -266,7 +266,7 @@ private String resolveImplementedInterfaces(TemplateContext templateContext) {
   private Map<String, List<String>> buildableReferences(TemplateContext templateContext, List<Map<String, Object>> fields) {
     final List<String> references = new ArrayList<>(settings.getBuildableReferences());
     references.add(0, settings.getObjectMetaClass());
-    if (fields.stream().map(f -> f.get("type")).map(Object::toString)
+    if (fields.stream().map(f -> f.get("type")).filter(Objects::nonNull).map(Object::toString)
         .anyMatch(r -> r.contains("KubernetesResource") || r.contains("HasMetadata") || r.contains("RawExtension"))) {
       references.add(settings.getGenericKubernetesResourceClass());
       references.add(settings.getRawExtensionClass());