diff --git a/src/openApi/v3/parser/getModel.ts b/src/openApi/v3/parser/getModel.ts
index 0393cc999..8c79d8397 100644
--- a/src/openApi/v3/parser/getModel.ts
+++ b/src/openApi/v3/parser/getModel.ts
@@ -6,7 +6,7 @@ import { extendEnum } from './extendEnum';
 import { getEnum } from './getEnum';
 import { findModelComposition, getModelComposition } from './getModelComposition';
 import { getModelDefault } from './getModelDefault';
-import { getModelProperties } from './getModelProperties';
+import { getAdditionalPropertiesModel, getModelProperties } from './getModelProperties';
 import { getType } from './getType';
 
 export const getModel = (
@@ -103,33 +103,6 @@ export const getModel = (
         return model;
     }
 
-    if (
-        definition.type === 'object' &&
-        (typeof definition.additionalProperties === 'object' || definition.additionalProperties === true)
-    ) {
-        const ap = typeof definition.additionalProperties === 'object' ? definition.additionalProperties : {};
-        if (ap.$ref) {
-            const additionalProperties = getType(ap.$ref);
-            model.export = 'dictionary';
-            model.type = additionalProperties.type;
-            model.base = additionalProperties.base;
-            model.template = additionalProperties.template;
-            model.imports.push(...additionalProperties.imports);
-            model.default = getModelDefault(definition, model);
-            return model;
-        } else {
-            const additionalProperties = getModel(openApi, ap);
-            model.export = 'dictionary';
-            model.type = additionalProperties.type;
-            model.base = additionalProperties.base;
-            model.template = additionalProperties.template;
-            model.link = additionalProperties;
-            model.imports.push(...additionalProperties.imports);
-            model.default = getModelDefault(definition, model);
-            return model;
-        }
-    }
-
     const foundComposition = findModelComposition(definition);
     if (foundComposition) {
         const composition = getModelComposition({
@@ -158,18 +131,16 @@ export const getModel = (
                     model.enums.push(modelProperty);
                 }
             });
-            return model;
-        } else {
-            const additionalProperties = getModel(openApi, {});
-            model.export = 'dictionary';
-            model.type = additionalProperties.type;
-            model.base = additionalProperties.base;
-            model.template = additionalProperties.template;
-            model.link = additionalProperties;
-            model.imports.push(...additionalProperties.imports);
-            model.default = getModelDefault(definition, model);
+
+            if (definition.additionalProperties === true) {
+                const modelProperty = getAdditionalPropertiesModel(openApi, definition, getModel, model);
+                model.properties.push(modelProperty);
+            }
+
             return model;
         }
+
+        return getAdditionalPropertiesModel(openApi, definition, getModel, model);
     }
 
     if (definition.const !== undefined) {
diff --git a/src/openApi/v3/parser/getModelProperties.ts b/src/openApi/v3/parser/getModelProperties.ts
index 6e25ca833..e054bf9ed 100644
--- a/src/openApi/v3/parser/getModelProperties.ts
+++ b/src/openApi/v3/parser/getModelProperties.ts
@@ -5,11 +5,50 @@ import type { OpenApi } from '../interfaces/OpenApi';
 import type { OpenApiSchema } from '../interfaces/OpenApiSchema';
 import { escapeName } from './escapeName';
 import type { getModel } from './getModel';
+import { getModelDefault } from './getModelDefault';
 import { getType } from './getType';
 
 // Fix for circular dependency
 export type GetModelFn = typeof getModel;
 
+export const getAdditionalPropertiesModel = (
+    openApi: OpenApi,
+    definition: OpenApiSchema,
+    getModel: GetModelFn,
+    model: Model
+): Model => {
+    const ap = typeof definition.additionalProperties === 'object' ? definition.additionalProperties : {};
+    const apModel = getModel(openApi, ap);
+
+    if (definition.additionalProperties === true && definition.properties) {
+        apModel.default = getModelDefault(definition, model);
+        apModel.export = 'generic';
+        apModel.isRequired = true;
+        apModel.name = '[key: string]';
+        return apModel;
+    }
+
+    if (ap.$ref) {
+        const apType = getType(ap.$ref);
+        model.base = apType.base;
+        model.default = getModelDefault(definition, model);
+        model.export = 'dictionary';
+        model.imports.push(...apType.imports);
+        model.template = apType.template;
+        model.type = apType.type;
+        return model;
+    }
+
+    model.base = apModel.base;
+    model.default = getModelDefault(definition, model);
+    model.export = 'dictionary';
+    model.imports.push(...apModel.imports);
+    model.link = apModel;
+    model.template = apModel.template;
+    model.type = apModel.type;
+    return model;
+};
+
 export const getModelProperties = (
     openApi: OpenApi,
     definition: OpenApiSchema,
diff --git a/test/__snapshots__/index.spec.ts.snap b/test/__snapshots__/index.spec.ts.snap
index 10e585282..a2b043972 100644
--- a/test/__snapshots__/index.spec.ts.snap
+++ b/test/__snapshots__/index.spec.ts.snap
@@ -3740,6 +3740,7 @@ export type { ModelCircle } from './models/ModelCircle';
 export type { ModelSquare } from './models/ModelSquare';
 export type { ModelThatExtends } from './models/ModelThatExtends';
 export type { ModelThatExtendsExtends } from './models/ModelThatExtendsExtends';
+export type { ModelWithAdditionalPropertiesEqTrue } from './models/ModelWithAdditionalPropertiesEqTrue';
 export type { ModelWithArray } from './models/ModelWithArray';
 export type { ModelWithBoolean } from './models/ModelWithBoolean';
 export type { ModelWithCircularReference } from './models/ModelWithCircularReference';
@@ -3819,6 +3820,7 @@ export { $ModelCircle } from './schemas/$ModelCircle';
 export { $ModelSquare } from './schemas/$ModelSquare';
 export { $ModelThatExtends } from './schemas/$ModelThatExtends';
 export { $ModelThatExtendsExtends } from './schemas/$ModelThatExtendsExtends';
+export { $ModelWithAdditionalPropertiesEqTrue } from './schemas/$ModelWithAdditionalPropertiesEqTrue';
 export { $ModelWithArray } from './schemas/$ModelWithArray';
 export { $ModelWithBoolean } from './schemas/$ModelWithBoolean';
 export { $ModelWithCircularReference } from './schemas/$ModelWithCircularReference';
@@ -4650,6 +4652,25 @@ export type ModelThatExtendsExtends = (ModelWithString & ModelThatExtends & {
 "
 `;
 
+exports[`v3 should generate: test/generated/v3/models/ModelWithAdditionalPropertiesEqTrue.ts 1`] = `
+"/* generated using openapi-typescript-codegen -- do no edit */
+/* istanbul ignore file */
+/* tslint:disable */
+/* eslint-disable */
+/**
+ * This is a model with one property and additionalProperties: true
+ */
+export type ModelWithAdditionalPropertiesEqTrue = {
+    /**
+     * This is a simple string property
+     */
+    prop?: string;
+    [key: string]: any;
+};
+
+"
+`;
+
 exports[`v3 should generate: test/generated/v3/models/ModelWithArray.ts 1`] = `
 "/* generated using openapi-typescript-codegen -- do no edit */
 /* istanbul ignore file */
@@ -6143,6 +6164,27 @@ export const $ModelThatExtendsExtends = {
 "
 `;
 
+exports[`v3 should generate: test/generated/v3/schemas/$ModelWithAdditionalPropertiesEqTrue.ts 1`] = `
+"/* generated using openapi-typescript-codegen -- do no edit */
+/* istanbul ignore file */
+/* tslint:disable */
+/* eslint-disable */
+export const $ModelWithAdditionalPropertiesEqTrue = {
+    description: \`This is a model with one property and additionalProperties: true\`,
+    properties: {
+        prop: {
+            type: 'string',
+            description: \`This is a simple string property\`,
+        },
+        [key: string]: {
+            type: 'any',
+            isRequired: true,
+        },
+    },
+} as const;
+"
+`;
+
 exports[`v3 should generate: test/generated/v3/schemas/$ModelWithArray.ts 1`] = `
 "/* generated using openapi-typescript-codegen -- do no edit */
 /* istanbul ignore file */
diff --git a/test/spec/v3.json b/test/spec/v3.json
index 70376f1ab..f1bb32e34 100644
--- a/test/spec/v3.json
+++ b/test/spec/v3.json
@@ -2737,6 +2737,17 @@
                     }
                 }
             },
+            "ModelWithAdditionalPropertiesEqTrue": {
+                "description": "This is a model with one property and additionalProperties: true",
+                "type": "object",
+                "properties": {
+                    "prop": {
+                        "description": "This is a simple string property",
+                        "type": "string"
+                    }
+                },
+                "additionalProperties": true
+            },
             "NestedAnyOfArraysNullable": {
                 "properties": {
                     "nullableArray": {