diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/ApiClient.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/ApiClient.mustache
index 1c068bcc58d..3969c08d391 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/ApiClient.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/ApiClient.mustache
@@ -153,6 +153,10 @@ public class ApiClient {
         );
         initHttpClient(Collections.<Interceptor>singletonList(retryingOAuth));
 {{/hasOAuthMethods}}
+        // Setup authentications (key: authentication name, value: authentication).{{#authMethods}}{{#isBasic}}{{#isBasicBasic}}
+        authentications.put("{{name}}", new HttpBasicAuth());{{/isBasicBasic}}{{^isBasicBasic}}
+        authentications.put("{{name}}", new HttpBearerAuth("{{scheme}}"));{{/isBasicBasic}}{{/isBasic}}{{#isApiKey}}
+        authentications.put("{{name}}", new ApiKeyAuth({{#isKeyInHeader}}"header"{{/isKeyInHeader}}{{#isKeyInQuery}}"query"{{/isKeyInQuery}}{{#isKeyInCookie}}"cookie"{{/isKeyInCookie}}, "{{keyParamName}}"));{{/isApiKey}}{{/authMethods}}
 
         // Prevent the authentications from being modified.
         authentications = Collections.unmodifiableMap(authentications);
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/ApiClient.java
index cde3509dbb0..b4072319ad5 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/ApiClient.java
@@ -143,6 +143,10 @@ public class ApiClient {
                 retryingOAuth
         );
         initHttpClient(Collections.<Interceptor>singletonList(retryingOAuth));
+        // Setup authentications (key: authentication name, value: authentication).
+        authentications.put("api_key", new ApiKeyAuth("header", "api_key"));
+        authentications.put("api_key_query", new ApiKeyAuth("query", "api_key_query"));
+        authentications.put("http_basic_test", new HttpBasicAuth());
 
         // Prevent the authentications from being modified.
         authentications = Collections.unmodifiableMap(authentications);
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/ApiClient.java
index cde3509dbb0..b4072319ad5 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/ApiClient.java
@@ -143,6 +143,10 @@ public class ApiClient {
                 retryingOAuth
         );
         initHttpClient(Collections.<Interceptor>singletonList(retryingOAuth));
+        // Setup authentications (key: authentication name, value: authentication).
+        authentications.put("api_key", new ApiKeyAuth("header", "api_key"));
+        authentications.put("api_key_query", new ApiKeyAuth("query", "api_key_query"));
+        authentications.put("http_basic_test", new HttpBasicAuth());
 
         // Prevent the authentications from being modified.
         authentications = Collections.unmodifiableMap(authentications);