diff --git a/_ba/tour/generic-classes.md b/_ba/tour/generic-classes.md
index c86d8f3f8f..9d85eee471 100644
--- a/_ba/tour/generic-classes.md
+++ b/_ba/tour/generic-classes.md
@@ -22,7 +22,8 @@ Konvencija je da se koristi slovo `A` kao identifikator tipa, mada se može kori
 ```tut
 class Stack[A] {
   private var elements: List[A] = Nil
-  def push(x: A) { elements = x :: elements }
+  def push(x: A): Unit =
+    elements = x :: elements
   def peek: A = elements.head
   def pop(): A = {
     val currentTop = peek
diff --git a/_es/tour/generic-classes.md b/_es/tour/generic-classes.md
index 60d7626cab..2a1ed5a2ba 100644
--- a/_es/tour/generic-classes.md
+++ b/_es/tour/generic-classes.md
@@ -16,7 +16,8 @@ A continuación se muestra un ejemplo:
 
     class Stack[T] {
       var elems: List[T] = Nil
-      def push(x: T) { elems = x :: elems }
+      def push(x: T): Unit =
+    	elems = x :: elems
       def top: T = elems.head
       def pop() { elems = elems.tail }
     }
diff --git a/_ja/tour/generic-classes.md b/_ja/tour/generic-classes.md
index 8e04bacd92..338a71b68c 100644
--- a/_ja/tour/generic-classes.md
+++ b/_ja/tour/generic-classes.md
@@ -21,7 +21,8 @@ assumed-knowledge: classes unified-types
 ```tut
 class Stack[A] {
   private var elements: List[A] = Nil
-  def push(x: A) { elements = x :: elements }
+  def push(x: A): Unit =
+    elements = x :: elements
   def peek: A = elements.head
   def pop(): A = {
     val currentTop = peek
diff --git a/_ko/tour/generic-classes.md b/_ko/tour/generic-classes.md
index e9f0d66e57..724514f338 100644
--- a/_ko/tour/generic-classes.md
+++ b/_ko/tour/generic-classes.md
@@ -14,7 +14,8 @@ previous-page: extractor-objects
 
     class Stack[T] {
       var elems: List[T] = Nil
-      def push(x: T) { elems = x :: elems }
+      def push(x: T): Unit =
+        elems = x :: elems
       def top: T = elems.head
       def pop() { elems = elems.tail }
     }
diff --git a/_pl/tour/generic-classes.md b/_pl/tour/generic-classes.md
index 5552d9931f..0db4768aff 100644
--- a/_pl/tour/generic-classes.md
+++ b/_pl/tour/generic-classes.md
@@ -16,7 +16,8 @@ Poniższy przykład demonstruje zastosowanie parametrów generycznych:
 ```tut
 class Stack[T] {
   var elems: List[T] = Nil
-  def push(x: T) { elems = x :: elems }
+  def push(x: T): Unit =
+    elems = x :: elems 
   def top: T = elems.head
   def pop() { elems = elems.tail }
 }
diff --git a/_pt-br/tour/generic-classes.md b/_pt-br/tour/generic-classes.md
index 82234c4636..253bbf84f2 100644
--- a/_pt-br/tour/generic-classes.md
+++ b/_pt-br/tour/generic-classes.md
@@ -15,7 +15,8 @@ Aqui temos um exemplo que demonstra isso:
 ```tut
 class Stack[T] {
   var elems: List[T] = Nil
-  def push(x: T) { elems = x :: elems }
+  def push(x: T): Unit =
+    elems = x :: elems
   def top: T = elems.head
   def pop() { elems = elems.tail }
 }
diff --git a/_ru/tour/generic-classes.md b/_ru/tour/generic-classes.md
index 30587567ca..082fa2bf67 100644
--- a/_ru/tour/generic-classes.md
+++ b/_ru/tour/generic-classes.md
@@ -20,7 +20,8 @@ assumed-knowledge: classes unified-types
 ```tut
 class Stack[A] {
   private var elements: List[A] = Nil
-  def push(x: A) { elements = x :: elements }
+  def push(x: A): Unit =
+    elements = x :: elements
   def peek: A = elements.head
   def pop(): A = {
     val currentTop = peek
diff --git a/_zh-cn/tour/generic-classes.md b/_zh-cn/tour/generic-classes.md
index 944105906c..93fba67d39 100644
--- a/_zh-cn/tour/generic-classes.md
+++ b/_zh-cn/tour/generic-classes.md
@@ -17,7 +17,8 @@ previous-page: extractor-objects
 ```tut
 class Stack[A] {
   private var elements: List[A] = Nil
-  def push(x: A) { elements = x :: elements }
+  def push(x: A): Unit =
+    elements = x :: elements 
   def peek: A = elements.head
   def pop(): A = {
     val currentTop = peek