diff --git a/src/main/java/com/canelmas/kafka/connect/FieldAndTimeBasedPartitioner.java b/src/main/java/com/canelmas/kafka/connect/FieldAndTimeBasedPartitioner.java
index c5eb5eb..dddfe6a 100644
--- a/src/main/java/com/canelmas/kafka/connect/FieldAndTimeBasedPartitioner.java
+++ b/src/main/java/com/canelmas/kafka/connect/FieldAndTimeBasedPartitioner.java
@@ -98,7 +98,7 @@ public String extract(final ConnectRecord<?> record) {
 
                 if (value instanceof Struct || value instanceof Map) {
 
-                    final String partitionField = (String) DataUtils.getNestedFieldValue(value, fieldName);
+                    final String partitionField = String.valueOf(DataUtils.getNestedFieldValue(value, fieldName));
 
                     if (formatPath) {
                         builder.append(String.join(DELIMITER_EQ, fieldName, partitionField));