diff --git a/src/main/java/ch/psi/daq/queryrest/response/csv/QueryFieldStringifyer.java b/src/main/java/ch/psi/daq/queryrest/response/csv/QueryFieldStringifyer.java
index 476c02b..7e78c11 100644
--- a/src/main/java/ch/psi/daq/queryrest/response/csv/QueryFieldStringifyer.java
+++ b/src/main/java/ch/psi/daq/queryrest/response/csv/QueryFieldStringifyer.java
@@ -1,9 +1,10 @@
 package ch.psi.daq.queryrest.response.csv;
 
-import java.lang.reflect.Array;
 import java.util.function.Function;
 
+import ch.psi.daq.common.util.Arrays;
 import ch.psi.daq.domain.DataEvent;
+import ch.psi.data.collection.PrimitiveList;
 
 public class QueryFieldStringifyer implements Function<DataEvent, String> {
    public static final String OPEN_BRACKET = "[";
@@ -19,6 +20,7 @@ public class QueryFieldStringifyer implements Function<DataEvent, String> {
       this.arraySeparator = arraySeparator;
    }
 
+   @SuppressWarnings("rawtypes")
    @Override
    public String apply(DataEvent event) {
       if (event == null) {
@@ -28,24 +30,35 @@ public class QueryFieldStringifyer implements Function<DataEvent, String> {
       Object value = accessor.apply(event);
       if (value == null) {
          return nonValue;
+      } else if (value instanceof PrimitiveList) {
+         return toString((PrimitiveList) value, arraySeparator);
       } else if (value.getClass().isArray()) {
-         StringBuilder buf = new StringBuilder();
-
-         int length = Array.getLength(value);
-         buf.append(OPEN_BRACKET);
-         for (int i = 0; i < length;) {
-            buf.append(Array.get(value, i));
-
-            ++i;
-            if (i < length) {
-               buf.append(arraySeparator);
-            }
-         }
-         buf.append(CLOSE_BRACKET);
-
-         return buf.toString();
+         return Arrays.toString(value, arraySeparator);
       } else {
          return value.toString();
       }
    }
+
+   public static String toString(PrimitiveList<?> value, String arraySeparator) {
+      int size = value.size();
+      if (size < 1) {
+         return Arrays.NULL_STRING;
+      } else if (size == 1) {
+         // scalar
+         return value.getAsString(0);
+      } else {
+         int iMax = size - 1;
+         if (iMax == -1)
+            return Arrays.EMPTY_ARRAY;
+
+         StringBuilder b = new StringBuilder();
+         b.append(OPEN_BRACKET);
+         for (int i = 0;; i++) {
+            b.append(value.getAsString(i));
+            if (i == iMax)
+               return b.append(CLOSE_BRACKET).toString();
+            b.append(arraySeparator);
+         }
+      }
+   }
 }
diff --git a/src/test/java/ch/psi/daq/test/queryrest/controller/CSVQueryRestControllerTest.java b/src/test/java/ch/psi/daq/test/queryrest/controller/CSVQueryRestControllerTest.java
index 0f109f3..8390cd1 100644
--- a/src/test/java/ch/psi/daq/test/queryrest/controller/CSVQueryRestControllerTest.java
+++ b/src/test/java/ch/psi/daq/test/queryrest/controller/CSVQueryRestControllerTest.java
@@ -492,7 +492,7 @@ public class CSVQueryRestControllerTest extends AbstractDaqRestTest {
                assertEquals("" + TimeUtils.getMillis(TestTimeUtils.getTimeFromPulseId(pulse)), record.get(column++));
                assertEquals("[8]", record.get(column++));
                assertEquals("1", record.get(column++));
-               assertTrue(record.get(column).startsWith("["));
+               assertTrue(record.get(column).startsWith("["+pulse+","));
                assertTrue(record.get(column++).endsWith("]"));
             }
             ++pulse;