diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
index 6d6c631aec1e..9a5b8752c719 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
@@ -4849,6 +4849,8 @@ public CodegenOperation fromOperation(String path,
         } else {
             op.path = path;
         }
+        // remove backslash from path, e.g. /api/v2/GetPetById\\(\\) => /api/v2/GetPetById()
+        op.path = op.path.replace("\\", "");
 
         op.summary = escapeText(operation.getSummary());
         op.unescapedNotes = operation.getDescription();
diff --git a/modules/openapi-generator/src/test/resources/3_1/java/petstore.yaml b/modules/openapi-generator/src/test/resources/3_1/java/petstore.yaml
index 704dc12186d9..289489356c19 100644
--- a/modules/openapi-generator/src/test/resources/3_1/java/petstore.yaml
+++ b/modules/openapi-generator/src/test/resources/3_1/java/petstore.yaml
@@ -758,6 +758,13 @@ paths:
                     items:
                       "$ref": "#/components/schemas/myObject"
                   - type: 'null'
+  "/fake/path/backslash/GetPetById\\(\\)":
+    get:
+      tags:
+        - fake
+      responses:
+        '200':
+          description: ''
 externalDocs:
   description: Find out more about Swagger
   url: 'http://swagger.io'
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/README.md b/samples/client/petstore/java/okhttp-gson-3.1/README.md
index 323f47a8c822..d5b9aa7acf13 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/README.md
+++ b/samples/client/petstore/java/okhttp-gson-3.1/README.md
@@ -116,6 +116,7 @@ Class | Method | HTTP request | Description
 *FakeApi* | [**fakeInlineSchemaAnyofPath1Get**](docs/FakeApi.md#fakeInlineSchemaAnyofPath1Get) | **GET** /fake/inline/schema/anyof/path1 | 
 *FakeApi* | [**fakeInlineSchemaAnyofPath2Get**](docs/FakeApi.md#fakeInlineSchemaAnyofPath2Get) | **GET** /fake/inline/schema/anyof/path2 | 
 *FakeApi* | [**fakeInlineSchemaAnyofPath3Get**](docs/FakeApi.md#fakeInlineSchemaAnyofPath3Get) | **GET** /fake/inline/schema/anyof/path3 | 
+*FakeApi* | [**fakePathBackslashGetPetByIdGet**](docs/FakeApi.md#fakePathBackslashGetPetByIdGet) | **GET** /fake/path/backslash/GetPetById() | 
 *FakeApi* | [**op1**](docs/FakeApi.md#op1) | **POST** /fake/api/changeowner | op1
 *FakeApi* | [**op2**](docs/FakeApi.md#op2) | **POST** /fake/api/changename | op2
 *FakeApi* | [**op3**](docs/FakeApi.md#op3) | **POST** /fake/api/query/enum | op3
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/api/openapi.yaml b/samples/client/petstore/java/okhttp-gson-3.1/api/openapi.yaml
index 45d0e4167627..82069b6831c1 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/api/openapi.yaml
+++ b/samples/client/petstore/java/okhttp-gson-3.1/api/openapi.yaml
@@ -834,6 +834,15 @@ paths:
       - fake
       x-accepts:
       - application/json
+  /fake/path/backslash/GetPetById\(\):
+    get:
+      responses:
+        "200":
+          description: ""
+      tags:
+      - fake
+      x-accepts:
+      - application/json
 components:
   parameters:
     ref_to_uuid:
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/docs/FakeApi.md b/samples/client/petstore/java/okhttp-gson-3.1/docs/FakeApi.md
index 684e019ef94d..79cb9e4dd28f 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/docs/FakeApi.md
+++ b/samples/client/petstore/java/okhttp-gson-3.1/docs/FakeApi.md
@@ -7,6 +7,7 @@ All URIs are relative to *http://petstore.swagger.io/v2*
 | [**fakeInlineSchemaAnyofPath1Get**](FakeApi.md#fakeInlineSchemaAnyofPath1Get) | **GET** /fake/inline/schema/anyof/path1 |  |
 | [**fakeInlineSchemaAnyofPath2Get**](FakeApi.md#fakeInlineSchemaAnyofPath2Get) | **GET** /fake/inline/schema/anyof/path2 |  |
 | [**fakeInlineSchemaAnyofPath3Get**](FakeApi.md#fakeInlineSchemaAnyofPath3Get) | **GET** /fake/inline/schema/anyof/path3 |  |
+| [**fakePathBackslashGetPetByIdGet**](FakeApi.md#fakePathBackslashGetPetByIdGet) | **GET** /fake/path/backslash/GetPetById() |  |
 | [**op1**](FakeApi.md#op1) | **POST** /fake/api/changeowner | op1 |
 | [**op2**](FakeApi.md#op2) | **POST** /fake/api/changename | op2 |
 | [**op3**](FakeApi.md#op3) | **POST** /fake/api/query/enum | op3 |
@@ -186,6 +187,61 @@ No authorization required
 |-------------|-------------|------------------|
 | **200** |  |  -  |
 
+<a id="fakePathBackslashGetPetByIdGet"></a>
+# **fakePathBackslashGetPetByIdGet**
+> fakePathBackslashGetPetByIdGet()
+
+
+
+### Example
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.FakeApi;
+
+public class Example {
+  public static void main(String[] args) {
+    ApiClient defaultClient = Configuration.getDefaultApiClient();
+    defaultClient.setBasePath("http://petstore.swagger.io/v2");
+
+    FakeApi apiInstance = new FakeApi(defaultClient);
+    try {
+      apiInstance.fakePathBackslashGetPetByIdGet();
+    } catch (ApiException e) {
+      System.err.println("Exception when calling FakeApi#fakePathBackslashGetPetByIdGet");
+      System.err.println("Status code: " + e.getCode());
+      System.err.println("Reason: " + e.getResponseBody());
+      System.err.println("Response headers: " + e.getResponseHeaders());
+      e.printStackTrace();
+    }
+  }
+}
+```
+
+### Parameters
+This endpoint does not need any parameter.
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: Not defined
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** |  |  -  |
+
 <a id="op1"></a>
 # **op1**
 > Object op1()
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/api/FakeApi.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/api/FakeApi.java
index eefccaf26854..afe7f7bfea57 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/api/FakeApi.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/api/FakeApi.java
@@ -426,6 +426,118 @@ public okhttp3.Call fakeInlineSchemaAnyofPath3GetAsync(final ApiCallback<List<Ob
         localVarApiClient.executeAsync(localVarCall, localVarReturnType, _callback);
         return localVarCall;
     }
+    /**
+     * Build call for fakePathBackslashGetPetByIdGet
+     * @param _callback Callback for upload/download progress
+     * @return Call to execute
+     * @throws ApiException If fail to serialize the request body object
+     * @http.response.details
+     <table border="1">
+       <caption>Response Details</caption>
+        <tr><td> Status Code </td><td> Description </td><td> Response Headers </td></tr>
+        <tr><td> 200 </td><td>  </td><td>  -  </td></tr>
+     </table>
+     */
+    public okhttp3.Call fakePathBackslashGetPetByIdGetCall(final ApiCallback _callback) throws ApiException {
+        String basePath = null;
+        // Operation Servers
+        String[] localBasePaths = new String[] {  };
+
+        // Determine Base Path to Use
+        if (localCustomBaseUrl != null){
+            basePath = localCustomBaseUrl;
+        } else if ( localBasePaths.length > 0 ) {
+            basePath = localBasePaths[localHostIndex];
+        } else {
+            basePath = null;
+        }
+
+        Object localVarPostBody = null;
+
+        // create path and map variables
+        String localVarPath = "/fake/path/backslash/GetPetById()";
+
+        List<Pair> localVarQueryParams = new ArrayList<Pair>();
+        List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+        Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+        Map<String, String> localVarCookieParams = new HashMap<String, String>();
+        Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+        final String[] localVarAccepts = {
+        };
+        final String localVarAccept = localVarApiClient.selectHeaderAccept(localVarAccepts);
+        if (localVarAccept != null) {
+            localVarHeaderParams.put("Accept", localVarAccept);
+        }
+
+        final String[] localVarContentTypes = {
+        };
+        final String localVarContentType = localVarApiClient.selectHeaderContentType(localVarContentTypes);
+        if (localVarContentType != null) {
+            localVarHeaderParams.put("Content-Type", localVarContentType);
+        }
+
+        String[] localVarAuthNames = new String[] {  };
+        return localVarApiClient.buildCall(basePath, localVarPath, "GET", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAuthNames, _callback);
+    }
+
+    @SuppressWarnings("rawtypes")
+    private okhttp3.Call fakePathBackslashGetPetByIdGetValidateBeforeCall(final ApiCallback _callback) throws ApiException {
+        return fakePathBackslashGetPetByIdGetCall(_callback);
+
+    }
+
+    /**
+     * 
+     * 
+     * @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body
+     * @http.response.details
+     <table border="1">
+       <caption>Response Details</caption>
+        <tr><td> Status Code </td><td> Description </td><td> Response Headers </td></tr>
+        <tr><td> 200 </td><td>  </td><td>  -  </td></tr>
+     </table>
+     */
+    public void fakePathBackslashGetPetByIdGet() throws ApiException {
+        fakePathBackslashGetPetByIdGetWithHttpInfo();
+    }
+
+    /**
+     * 
+     * 
+     * @return ApiResponse&lt;Void&gt;
+     * @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body
+     * @http.response.details
+     <table border="1">
+       <caption>Response Details</caption>
+        <tr><td> Status Code </td><td> Description </td><td> Response Headers </td></tr>
+        <tr><td> 200 </td><td>  </td><td>  -  </td></tr>
+     </table>
+     */
+    public ApiResponse<Void> fakePathBackslashGetPetByIdGetWithHttpInfo() throws ApiException {
+        okhttp3.Call localVarCall = fakePathBackslashGetPetByIdGetValidateBeforeCall(null);
+        return localVarApiClient.execute(localVarCall);
+    }
+
+    /**
+     *  (asynchronously)
+     * 
+     * @param _callback The callback to be executed when the API call finishes
+     * @return The request call
+     * @throws ApiException If fail to process the API call, e.g. serializing the request body object
+     * @http.response.details
+     <table border="1">
+       <caption>Response Details</caption>
+        <tr><td> Status Code </td><td> Description </td><td> Response Headers </td></tr>
+        <tr><td> 200 </td><td>  </td><td>  -  </td></tr>
+     </table>
+     */
+    public okhttp3.Call fakePathBackslashGetPetByIdGetAsync(final ApiCallback<Void> _callback) throws ApiException {
+
+        okhttp3.Call localVarCall = fakePathBackslashGetPetByIdGetValidateBeforeCall(_callback);
+        localVarApiClient.executeAsync(localVarCall, _callback);
+        return localVarCall;
+    }
     /**
      * Build call for op1
      * @param _callback Callback for upload/download progress