diff --git a/src/main/java/eu/hbp/mip/utils/DataUtil.java b/src/main/java/eu/hbp/mip/utils/DataUtil.java
index 3d1d872d779766dc2948b3ff66a751ce0afedca8..2e93bbed20ec75059d55c2e23e1c30270623c2be 100644
--- a/src/main/java/eu/hbp/mip/utils/DataUtil.java
+++ b/src/main/java/eu/hbp/mip/utils/DataUtil.java
@@ -39,8 +39,11 @@ public class DataUtil {
 
                 long nb_samples = Math.min(nbRows, MAX_NB_SAMPLES);
                 int samplingPercentage = (int) (100 * nb_samples / nbRows);
+                if (filters.length() > 0) {
+                    filters = "WHERE " + filters;
+                }
                 List<Object> queryResult = jdbcTemplate.queryForList(
-                        String.format("SELECT %s FROM %s TABLESAMPLE SYSTEM (%d) REPEATABLE (%d) WHERE %s",
+                        String.format("SELECT %s FROM %s TABLESAMPLE SYSTEM (%d) REPEATABLE (%d) %s",
                                 var, featuresMainTable, samplingPercentage, TABLESAMPLE_SEED, filters),
                         Object.class);
                 for (Object value : queryResult) {