diff --git a/src/main/resources/handlebars/Java/libraries/jersey2/api.mustache b/src/main/resources/handlebars/Java/libraries/jersey2/api.mustache
index 6e0dda863e..826a2c618e 100644
--- a/src/main/resources/handlebars/Java/libraries/jersey2/api.mustache
+++ b/src/main/resources/handlebars/Java/libraries/jersey2/api.mustache
@@ -26,6 +26,7 @@ import java.util.Map;
 {{#operations}}
 public class {{classname}} {
   private ApiClient {{localVariablePrefix}}apiClient;
+  private Map<String, String> headers;
 
   public {{classname}}() {
     this(Configuration.getDefaultApiClient());
@@ -43,6 +44,10 @@ public class {{classname}} {
     this.{{localVariablePrefix}}apiClient = apiClient;
   }
 
+  public void setHeadersOverrides(Map<String, String> headers) {
+    this.headers = headers;
+  }
+
   {{#operation}}
   {{#contents}}
   /**
@@ -114,8 +119,18 @@ public class {{classname}} {
 
     {{#returnType}}
     GenericType<{{{returnType}}}> {{localVariablePrefix}}localVarReturnType = new GenericType<{{{returnType}}}>() {};
+
+    if (headers != null) {
+      localVarHeaderParams.putAll(headers);
+    }
+
     return {{localVariablePrefix}}apiClient.invokeAPI({{localVariablePrefix}}localVarPath, "{{httpMethod}}", {{localVariablePrefix}}localVarQueryParams, {{localVariablePrefix}}localVarPostBody, {{localVariablePrefix}}localVarHeaderParams, {{localVariablePrefix}}localVarFormParams, {{localVariablePrefix}}localVarAccept, {{localVariablePrefix}}localVarContentType, {{localVariablePrefix}}localVarAuthNames, {{localVariablePrefix}}localVarReturnType);
     {{/returnType}}{{^returnType}}
+
+    if (headers != null) {
+      localVarHeaderParams.putAll(headers);
+    }
+
     {{localVariablePrefix}}apiClient.invokeAPI({{localVariablePrefix}}localVarPath, "{{httpMethod}}", {{localVariablePrefix}}localVarQueryParams, {{localVariablePrefix}}localVarPostBody, {{localVariablePrefix}}localVarHeaderParams, {{localVariablePrefix}}localVarFormParams, {{localVariablePrefix}}localVarAccept, {{localVariablePrefix}}localVarContentType, {{localVariablePrefix}}localVarAuthNames, null);
     {{/returnType}}
   }
diff --git a/src/main/resources/handlebars/Java/libraries/okhttp-gson/api.mustache b/src/main/resources/handlebars/Java/libraries/okhttp-gson/api.mustache
index b1033181f5..ff1785a32f 100644
--- a/src/main/resources/handlebars/Java/libraries/okhttp-gson/api.mustache
+++ b/src/main/resources/handlebars/Java/libraries/okhttp-gson/api.mustache
@@ -58,6 +58,7 @@ import java.util.Map;
 {{#operations}}
 public class {{classname}} {
     private ApiClient {{localVariablePrefix}}apiClient;
+    private Map<String, String> headers;
 
     public {{classname}}() {
         this(Configuration.getDefaultApiClient());
@@ -75,6 +76,10 @@ public class {{classname}} {
         this.{{localVariablePrefix}}apiClient = apiClient;
     }
 
+    public void setHeadersOverrides(Map<String, String> headers) {
+        this.headers = headers;
+    }
+
     {{#operation}}
     {{#contents}}
     /**
@@ -138,6 +143,9 @@ public class {{classname}} {
         }
 
         String[] {{localVariablePrefix}}localVarAuthNames = new String[] { {{#authMethods}}"{{name}}"{{#has this 'more'}}, {{/has}}{{/authMethods}} };
+        if (headers != null) {
+            localVarHeaderParams.putAll(headers);
+        }
         return {{localVariablePrefix}}apiClient.buildCall({{localVariablePrefix}}localVarPath, "{{httpMethod}}", {{localVariablePrefix}}localVarQueryParams, {{localVariablePrefix}}localVarCollectionQueryParams, {{localVariablePrefix}}localVarPostBody, {{localVariablePrefix}}localVarHeaderParams, {{localVariablePrefix}}localVarFormParams, {{localVariablePrefix}}localVarAuthNames, progressRequestListener);
     }