diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/external-library/upperCase/upperCase.3.query.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/external-library/upperCase/upperCase.3.query.sqlpp
index 743d39a..62c2b87 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/external-library/upperCase/upperCase.3.query.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/external-library/upperCase/upperCase.3.query.sqlpp
@@ -18,7 +18,7 @@
  */
 use externallibtest;
 
-let i={"id":1, "text_list": [{"text":"lower text1"}, {"text":"lower text2"}]}
+let i={"id":1, "text_list": [{"text":"lower text1"}, {"text":"lower text2"}], "another_list" : ["string_1", "string_2"]}
 select value `testlib#toUpper`(i);
 
 let i=`testlib#toUpper`({"id":1, "text_list":[{"text":"lower text"}]})
diff --git a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/library/java/JObjectAccessors.java b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/library/java/JObjectAccessors.java
index ee8308f..3af08fa 100644
--- a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/library/java/JObjectAccessors.java
+++ b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/library/java/JObjectAccessors.java
@@ -583,10 +583,20 @@
         public IJObject access(AListVisitablePointable pointable, IObjectPool<IJObject, IAType> objectPool,
                 IAType listType, JObjectPointableVisitor pointableVisitor) throws HyracksDataException {
             List<IVisitablePointable> items = pointable.getItems();
+            List<IVisitablePointable> itemTags = pointable.getItemTags();
             JList list = pointable.ordered() ? new JOrderedList(listType) : new JUnorderedList(listType);
             IJObject listItem;
-            for (IVisitablePointable itemPointable : items) {
-                final IAType fieldType = ((AbstractCollectionType) listType).getItemType();
+            for (int iter1 = 0; iter1 < items.size(); iter1++) {
+                IVisitablePointable itemPointable = items.get(iter1);
+                // First, try to get defined type.
+                IAType fieldType = ((AbstractCollectionType) listType).getItemType();
+                if (fieldType.getTypeTag() == ATypeTag.ANY) {
+                    // Second, if defined type is not available, try to infer it from data
+                    IVisitablePointable itemTagPointable = itemTags.get(iter1);
+                    ATypeTag itemTypeTag = EnumDeserializer.ATYPETAGDESERIALIZER
+                            .deserialize(itemTagPointable.getByteArray()[itemTagPointable.getStartOffset()]);
+                    fieldType = TypeTagUtil.getBuiltinTypeByTag(itemTypeTag);
+                }
                 typeInfo.reset(fieldType, fieldType.getTypeTag());
                 switch (typeInfo.getTypeTag()) {
                     case OBJECT: