diff --git a/openapi-generator/src/main/java/io/micronaut/openapi/generator/AbstractMicronautJavaCodegen.java b/openapi-generator/src/main/java/io/micronaut/openapi/generator/AbstractMicronautJavaCodegen.java
index 98e79da8c5..efbcc6c87e 100644
--- a/openapi-generator/src/main/java/io/micronaut/openapi/generator/AbstractMicronautJavaCodegen.java
+++ b/openapi-generator/src/main/java/io/micronaut/openapi/generator/AbstractMicronautJavaCodegen.java
@@ -786,14 +786,46 @@ public Map<String, ModelsMap> postProcessAllModels(Map<String, ModelsMap> objs)
 
         for (ModelsMap models : objs.values()) {
             CodegenModel model = models.getModels().get(0).getModel();
-            if (model.getParentModel() != null) {
-                model.vendorExtensions.put("requiredParentVars", model.getParentModel().requiredVars);
+
+            var hasParent = model.getParentModel() != null;
+            var requiredVarsWithoutDiscriminator = new ArrayList<CodegenProperty>();
+            for (var v : model.requiredVars) {
+                boolean isDiscriminator = false;
+                if (hasParent) {
+                    for (var pv : model.getParentModel().getAllVars()) {
+                        if (pv.required && pv.getName().equals(v.getName())) {
+                            isDiscriminator = pv.isDiscriminator;
+                            break;
+                        }
+                    }
+                } else {
+                    isDiscriminator = v.isDiscriminator;
+                }
+                if (!isDiscriminator) {
+                    requiredVarsWithoutDiscriminator.add(v);
+                }
+            }
+
+            if (hasParent) {
+                var parentRequiredVarsWithoutDiscriminator = new ArrayList<CodegenProperty>();
+                for (var v : model.getParentModel().vars) {
+                    if (v.required && !v.isDiscriminator) {
+                        parentRequiredVarsWithoutDiscriminator.add(v);
+                    }
+                }
+                model.vendorExtensions.put("requiredParentVarsWithoutDiscriminator", parentRequiredVarsWithoutDiscriminator);
                 model.parentVars = model.getParentModel().allVars;
             }
 
             List<CodegenProperty> requiredVars = model.vars.stream().filter(v -> v.required).collect(Collectors.toList());
+
+            model.vendorExtensions.put("requiredVarsWithoutDiscriminator", requiredVarsWithoutDiscriminator);
             model.vendorExtensions.put("requiredVars", requiredVars);
-            model.vendorExtensions.put("areRequiredVarsAndReadOnlyVars", !requiredVars.isEmpty() && !model.readOnlyVars.isEmpty());
+            model.vendorExtensions.put("areRequiredVarsAndReadOnlyVars", !requiredVarsWithoutDiscriminator.isEmpty() && !model.readOnlyVars.isEmpty());
+            if (model.discriminator != null) {
+                model.vendorExtensions.put("hasMappedModels", !model.discriminator.getMappedModels().isEmpty());
+                model.vendorExtensions.put("hasMultipleMappedModels", model.discriminator.getMappedModels().size() > 1);
+            }
         }
 
         return objs;
diff --git a/openapi-generator/src/main/resources/templates/java-micronaut/common/model/pojo.mustache b/openapi-generator/src/main/resources/templates/java-micronaut/common/model/pojo.mustache
index 6bed58f24e..0b5e758bb9 100644
--- a/openapi-generator/src/main/resources/templates/java-micronaut/common/model/pojo.mustache
+++ b/openapi-generator/src/main/resources/templates/java-micronaut/common/model/pojo.mustache
@@ -113,16 +113,17 @@ public class {{classname}} {{#parent}}extends {{{parent}}} {{/parent}}{{#vendorE
     {{/vars}}
 
     {{#requiredPropertiesInConstructor}}
-    public {{classname}}({{#requiredVars}}{{{datatypeWithEnum}}} {{name}}{{^-last}}, {{/-last}}{{/requiredVars}}{{#vendorExtensions.areRequiredVarsAndReadOnlyVars}}, {{/vendorExtensions.areRequiredVarsAndReadOnlyVars}}{{#readOnlyVars}}{{{datatypeWithEnum}}} {{name}}{{^-last}}, {{/-last}}{{/readOnlyVars}}) {
+    public {{classname}}({{#vendorExtensions.requiredVarsWithoutDiscriminator}}{{{datatypeWithEnum}}} {{name}}{{^-last}}, {{/-last}}{{/vendorExtensions.requiredVarsWithoutDiscriminator}}{{#vendorExtensions.areRequiredVarsAndReadOnlyVars}}, {{/vendorExtensions.areRequiredVarsAndReadOnlyVars}}{{#readOnlyVars}}{{{datatypeWithEnum}}} {{name}}{{^-last}}, {{/-last}}{{/readOnlyVars}}) {
         {{#parent}}
-        super({{#vendorExtensions.requiredParentVars}}{{name}}{{^-last}}, {{/-last}}{{/vendorExtensions.requiredParentVars}});
+        super({{#vendorExtensions.requiredParentVarsWithoutDiscriminator}}{{name}}{{^-last}}, {{/-last}}{{/vendorExtensions.requiredParentVarsWithoutDiscriminator}});
         {{/parent}}
         {{#vendorExtensions.requiredVars}}
+            {{^isDiscriminator}}
         this.{{name}} = {{name}};
+            {{/isDiscriminator}}
         {{/vendorExtensions.requiredVars}}
     }
     {{/requiredPropertiesInConstructor}}
-
     {{^requiredPropertiesInConstructor}}
     public {{classname}}() {
         {{#parent}}
diff --git a/openapi-generator/src/main/resources/templates/java-micronaut/common/model/typeInfoAnnotation.mustache b/openapi-generator/src/main/resources/templates/java-micronaut/common/model/typeInfoAnnotation.mustache
index 7d26adf444..c0232e5ce5 100644
--- a/openapi-generator/src/main/resources/templates/java-micronaut/common/model/typeInfoAnnotation.mustache
+++ b/openapi-generator/src/main/resources/templates/java-micronaut/common/model/typeInfoAnnotation.mustache
@@ -3,12 +3,17 @@
   value = "{{{discriminator.propertyBaseName}}}", // ignore manually set {{{discriminator.propertyBaseName}}}, it will be automatically generated by Jackson during serialization
   allowSetters = true // allows the {{{discriminator.propertyBaseName}}} to be set during deserialization
 )
-@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "{{{discriminator.propertyBaseName}}}"{{^micronaut_serde_jackson}}, visible = true{{/micronaut_serde_jackson}})
+@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, property = "{{{discriminator.propertyBaseName}}}"{{^micronaut_serde_jackson}}, visible = true{{/micronaut_serde_jackson}})
 {{#discriminator}}
-    {{#mappedModels.0}}
-@JsonSubTypes({ {{#mappedModels}}
+    {{#vendorExtensions.hasMappedModels}}
+        {{#vendorExtensions.hasMultipleMappedModels}}
+@JsonSubTypes({{openbrace}}{{#mappedModels}}
     @JsonSubTypes.Type(value = {{modelName}}.class, name = "{{^vendorExtensions.x-discriminator-value}}{{mappingName}}{{/vendorExtensions.x-discriminator-value}}{{#vendorExtensions.x-discriminator-value}}{{{vendorExtensions.x-discriminator-value}}}{{/vendorExtensions.x-discriminator-value}}"){{^-last}},{{/-last}}
-{{/mappedModels}}{{closebarace}})
-    {{/mappedModels.0}}
+{{/mappedModels}}{{closebrace}})
+        {{/vendorExtensions.hasMultipleMappedModels}}
+        {{^vendorExtensions.hasMultipleMappedModels}}
+@JsonSubTypes({{#mappedModels}}@JsonSubTypes.Type(value = {{modelName}}.class, name = "{{^vendorExtensions.x-discriminator-value}}{{mappingName}}{{/vendorExtensions.x-discriminator-value}}{{#vendorExtensions.x-discriminator-value}}{{{vendorExtensions.x-discriminator-value}}}{{/vendorExtensions.x-discriminator-value}}"){{/mappedModels}})
+        {{/vendorExtensions.hasMultipleMappedModels}}
+    {{/vendorExtensions.hasMappedModels}}
 {{/discriminator}}
 {{/jackson}}