diff --git a/src/main/java/be/cylab/java/wowa/training/Utils.java b/src/main/java/be/cylab/java/wowa/training/Utils.java
index d5a89263ae3b1348d43457ed2b39f06fe4798eb7..ced6a600378d7ac4248b591d08ca99a360b4f69c 100644
--- a/src/main/java/be/cylab/java/wowa/training/Utils.java
+++ b/src/main/java/be/cylab/java/wowa/training/Utils.java
@@ -8,6 +8,7 @@ import info.debatty.java.aggregation.WOWA;
 import org.apache.commons.lang3.ArrayUtils;
 
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.text.DateFormat;
@@ -131,7 +132,8 @@ public final class Utils {
             throws IOException {
 
         Genson genson = new Genson();
-        String data_json = new String(Files.readAllBytes(Paths.get(filename)));
+        String data_json = new String(Files.readAllBytes(Paths.get(filename)),
+                StandardCharsets.UTF_8);
         List<double[]> data = genson.deserialize(
                 data_json,
                 new GenericType<List<double[]>>() {
@@ -151,7 +153,8 @@ public final class Utils {
 
         Genson genson = new Genson();
         String expected_json = new String(
-                Files.readAllBytes(Paths.get(filename)));
+                Files.readAllBytes(Paths.get(filename)),
+                StandardCharsets.UTF_8);
         double[] expected = genson.deserialize(expected_json, double[].class);
         return expected;
     }