diff --git a/Main.java b/Main.java
index 875f05aa5209e4d717e453a56a3e845ba2a8e941..b8e6d9b575f0929ae2031dfc464503871cc30ff3 100644
--- a/Main.java
+++ b/Main.java
@@ -9,9 +9,9 @@ public class Main {
     public static void main(String[] args) throws Exception {
         System.out.println("Advanced Course in Object-Oriented Programming, Part 4 Exercises");
 
-        new Teht1();
-        new Teht2();
-        new Teht3();
-        new Teht4();
+        new Exercise1();
+        new Exercise2();
+        new Exercise3();
+        new Exercise4();
     }
 }
diff --git a/Exercise1/Exercise1.java b/exercise1/Exercise1.java
similarity index 100%
rename from Exercise1/Exercise1.java
rename to exercise1/Exercise1.java
diff --git a/Exercise1/TestZipper.java b/exercise1/TestZipper.java
similarity index 100%
rename from Exercise1/TestZipper.java
rename to exercise1/TestZipper.java
diff --git a/Exercise1/Zipper.java b/exercise1/Zipper.java
similarity index 100%
rename from Exercise1/Zipper.java
rename to exercise1/Zipper.java
diff --git a/Exercise2/Exercise2.java b/exercise2/Exercise2.java
similarity index 100%
rename from Exercise2/Exercise2.java
rename to exercise2/Exercise2.java
diff --git a/Exercise2/TestZipper.java b/exercise2/TestZipper.java
similarity index 100%
rename from Exercise2/TestZipper.java
rename to exercise2/TestZipper.java
diff --git a/Exercise3/Exercise3.java b/exercise3/Exercise3.java
similarity index 92%
rename from Exercise3/Exercise3.java
rename to exercise3/Exercise3.java
index eafdc309550677503c5ff585f7476f746a861d14..e0cb1a33e17605409acadad0eedf56b4c3334e4a 100644
--- a/Exercise3/Exercise3.java
+++ b/exercise3/Exercise3.java
@@ -26,7 +26,7 @@ class Crow extends Bird {
     }
 }
 
-public class Teht3 {
+public class Exercise3 {
     public Teht3() {
         System.out.println("Exercise 3");
 
diff --git a/Exercise4/Exercise4.java b/exercise4/Exercise4.java
similarity index 78%
rename from Exercise4/Exercise4.java
rename to exercise4/Exercise4.java
index d0fe9c2e9bf68e31e42716858b869df4cb4d6512..a233a0adce11f423c10923291a55a01a91893e0d 100644
--- a/Exercise4/Exercise4.java
+++ b/exercise4/Exercise4.java
@@ -1,6 +1,6 @@
 package fi.utu.tech.ooj.exercise4.exercise4;
 
-public class Teht4 {
+public class Exercise4 {
     public Teht4() {
         System.out.println("Exercise 4");
     }