diff --git a/modules/swagger-codegen/src/main/resources/Java/apiInvoker.mustache b/modules/swagger-codegen/src/main/resources/Java/apiInvoker.mustache
index eff710a044e3..28c27b3d16e1 100644
--- a/modules/swagger-codegen/src/main/resources/Java/apiInvoker.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/apiInvoker.mustache
@@ -53,6 +53,13 @@ public class ApiInvoker {
     // Use UTC as the default time zone.
     DATE_TIME_FORMAT.setTimeZone(TimeZone.getTimeZone("UTC"));
     DATE_FORMAT.setTimeZone(TimeZone.getTimeZone("UTC"));
+
+    // Set default User-Agent.
+    setUserAgent("Java-Swagger");
+  }
+
+  public static void setUserAgent(String userAgent) {
+    INSTANCE.addDefaultHeader("User-Agent", userAgent);
   }
 
   public static Date parseDateTime(String str) {
diff --git a/modules/swagger-codegen/src/main/resources/android-java/apiInvoker.mustache b/modules/swagger-codegen/src/main/resources/android-java/apiInvoker.mustache
index 8b31abd48abe..4c0aa2d3ed66 100644
--- a/modules/swagger-codegen/src/main/resources/android-java/apiInvoker.mustache
+++ b/modules/swagger-codegen/src/main/resources/android-java/apiInvoker.mustache
@@ -82,6 +82,13 @@ public class ApiInvoker {
     // Use UTC as the default time zone.
     DATE_TIME_FORMAT.setTimeZone(TimeZone.getTimeZone("UTC"));
     DATE_FORMAT.setTimeZone(TimeZone.getTimeZone("UTC"));
+
+    // Set default User-Agent.
+    setUserAgent("Android-Java-Swagger");
+  }
+
+  public static void setUserAgent(String userAgent) {
+    INSTANCE.addDefaultHeader("User-Agent", userAgent);
   }
 
   public static Date parseDateTime(String str) {
diff --git a/samples/client/petstore/android-java/src/main/java/io/swagger/client/ApiInvoker.java b/samples/client/petstore/android-java/src/main/java/io/swagger/client/ApiInvoker.java
index 9eb217fe7369..1c9980e9a23f 100644
--- a/samples/client/petstore/android-java/src/main/java/io/swagger/client/ApiInvoker.java
+++ b/samples/client/petstore/android-java/src/main/java/io/swagger/client/ApiInvoker.java
@@ -82,6 +82,13 @@ public class ApiInvoker {
     // Use UTC as the default time zone.
     DATE_TIME_FORMAT.setTimeZone(TimeZone.getTimeZone("UTC"));
     DATE_FORMAT.setTimeZone(TimeZone.getTimeZone("UTC"));
+
+    // Set default User-Agent.
+    setUserAgent("Android-Java-Swagger");
+  }
+
+  public static void setUserAgent(String userAgent) {
+    INSTANCE.addDefaultHeader("User-Agent", userAgent);
   }
 
   public static Date parseDateTime(String str) {
diff --git a/samples/client/petstore/java/src/main/java/io/swagger/client/ApiInvoker.java b/samples/client/petstore/java/src/main/java/io/swagger/client/ApiInvoker.java
index f3b3466dbdf6..231bff1e5302 100644
--- a/samples/client/petstore/java/src/main/java/io/swagger/client/ApiInvoker.java
+++ b/samples/client/petstore/java/src/main/java/io/swagger/client/ApiInvoker.java
@@ -53,6 +53,13 @@ public class ApiInvoker {
     // Use UTC as the default time zone.
     DATE_TIME_FORMAT.setTimeZone(TimeZone.getTimeZone("UTC"));
     DATE_FORMAT.setTimeZone(TimeZone.getTimeZone("UTC"));
+
+    // Set default User-Agent.
+    setUserAgent("Java-Swagger");
+  }
+
+  public static void setUserAgent(String userAgent) {
+    INSTANCE.addDefaultHeader("User-Agent", userAgent);
   }
 
   public static Date parseDateTime(String str) {