diff --git a/pom.xml b/pom.xml
index ab57eb53a..6937d906f 100644
--- a/pom.xml
+++ b/pom.xml
@@ -219,6 +219,21 @@
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-checkstyle-plugin</artifactId>
           <version>2.11</version>
+          <executions>
+            <execution>
+              <id>validate</id>
+              <phase>validate</phase>
+              <configuration>
+                <encoding>UTF-8</encoding>
+                <consoleOutput>true</consoleOutput>
+                <failsOnError>true</failsOnError>
+                <linkXRef>false</linkXRef>
+              </configuration>
+              <goals>
+                <goal>check</goal>
+              </goals>
+            </execution>
+          </executions>
           <configuration>
             <propertyExpansion>config_loc=${basedir}/..</propertyExpansion>
             <configLocation>../checkstyle.xml</configLocation>
diff --git a/teavm-samples/teavm-samples-benchmark/pom.xml b/teavm-samples/teavm-samples-benchmark/pom.xml
index 1f302e97d..4844ea982 100644
--- a/teavm-samples/teavm-samples-benchmark/pom.xml
+++ b/teavm-samples/teavm-samples-benchmark/pom.xml
@@ -74,7 +74,7 @@
     <dependency>
       <groupId>com.dukescript.canvas</groupId>
       <artifactId>html5-canvas</artifactId>
-      <version>0.7.1</version>
+      <version>0.7.2</version>
     </dependency>
     <dependency>
       <groupId>org.netbeans.html</groupId>
diff --git a/teavm-samples/teavm-samples-benchmark/src/main/java/org/teavm/samples/benchmark/htmljava/BenchmarkFX.java b/teavm-samples/teavm-samples-benchmark/src/main/java/org/teavm/samples/benchmark/htmljava/BenchmarkFX.java
index 2349c1e61..780cefcd2 100644
--- a/teavm-samples/teavm-samples-benchmark/src/main/java/org/teavm/samples/benchmark/htmljava/BenchmarkFX.java
+++ b/teavm-samples/teavm-samples-benchmark/src/main/java/org/teavm/samples/benchmark/htmljava/BenchmarkFX.java
@@ -1,23 +1,26 @@
 /*
- * Copyright 2015 jarda.
+ *  Copyright 2015 Jaroslav Tulach.
  *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
  *
- *      http://www.apache.org/licenses/LICENSE-2.0
+ *       http://www.apache.org/licenses/LICENSE-2.0
  *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
  */
 package org.teavm.samples.benchmark.htmljava;
 
 import net.java.html.boot.BrowserBuilder;
 
-public class BenchmarkFX {
+public final class BenchmarkFX {
+    private BenchmarkFX() {
+    }
+    
     public static void main(String... args) {
         BrowserBuilder.newBrowser().loadPage("fx.html")
             .loadClass(BenchmarkStarter.class)
diff --git a/teavm-samples/teavm-samples-benchmark/src/main/java/org/teavm/samples/benchmark/htmljava/BenchmarkStarter.java b/teavm-samples/teavm-samples-benchmark/src/main/java/org/teavm/samples/benchmark/htmljava/BenchmarkStarter.java
index a0606f347..a949a7d8a 100644
--- a/teavm-samples/teavm-samples-benchmark/src/main/java/org/teavm/samples/benchmark/htmljava/BenchmarkStarter.java
+++ b/teavm-samples/teavm-samples-benchmark/src/main/java/org/teavm/samples/benchmark/htmljava/BenchmarkStarter.java
@@ -1,17 +1,17 @@
 /*
- * Copyright 2015 Jaroslav Tulach.
+ *  Copyright 2015 Jaroslav Tulach.
  *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
  *
- *      http://www.apache.org/licenses/LICENSE-2.0
+ *       http://www.apache.org/licenses/LICENSE-2.0
  *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
  */
 package org.teavm.samples.benchmark.htmljava;
 
@@ -31,7 +31,10 @@ import org.jbox2d.dynamics.Body;
 import org.jbox2d.dynamics.Fixture;
 import org.teavm.samples.benchmark.Scene;
 
-public class BenchmarkStarter {
+public final class BenchmarkStarter {
+    private BenchmarkStarter() {
+    }
+    
     private static final Timer TIMER = new Timer("Make Step");
     private static final Scene scene = new Scene();
     private static double startMillisecond;