diff --git a/connect/transforms/src/test/java/org/apache/kafka/connect/transforms/CastTest.java b/connect/transforms/src/test/java/org/apache/kafka/connect/transforms/CastTest.java
index a28aa28c6d72e..c8dcd0adbc2f5 100644
--- a/connect/transforms/src/test/java/org/apache/kafka/connect/transforms/CastTest.java
+++ b/connect/transforms/src/test/java/org/apache/kafka/connect/transforms/CastTest.java
@@ -21,6 +21,7 @@
 import java.util.List;
 import java.util.concurrent.TimeUnit;
 import org.apache.kafka.common.config.ConfigException;
+import org.apache.kafka.common.utils.Utils;
 import org.apache.kafka.connect.data.Decimal;
 import org.apache.kafka.connect.data.Schema;
 import org.apache.kafka.connect.data.Schema.Type;
@@ -339,7 +340,7 @@ public void castLogicalToPrimitive() {
 
         Date day = new Date(MILLIS_PER_DAY);
         xformValue.configure(Collections.singletonMap(Cast.SPEC_CONFIG,
-            String.join(",", specParts)));
+            Utils.join(specParts, ",")));
 
         SchemaBuilder builder = SchemaBuilder.struct();
         builder.field("date_to_int32", org.apache.kafka.connect.data.Date.SCHEMA);