diff --git a/clients/src/main/java/org/apache/kafka/common/protocol/types/Struct.java b/clients/src/main/java/org/apache/kafka/common/protocol/types/Struct.java
index 7eee09f0de425..212d701aaaa84 100644
--- a/clients/src/main/java/org/apache/kafka/common/protocol/types/Struct.java
+++ b/clients/src/main/java/org/apache/kafka/common/protocol/types/Struct.java
@@ -290,7 +290,7 @@ public String toString() {
             Field f = this.schema.get(i);
             b.append(f.name);
             b.append('=');
-            if (f.type() instanceof ArrayOf) {
+            if (f.type() instanceof ArrayOf && this.values[i] != null) {
                 Object[] arrayValue = (Object[]) this.values[i];
                 b.append('[');
                 for (int j = 0; j < arrayValue.length; j++) {
diff --git a/clients/src/test/java/org/apache/kafka/common/protocol/types/ProtocolSerializationTest.java b/clients/src/test/java/org/apache/kafka/common/protocol/types/ProtocolSerializationTest.java
index e91b2fb591d4e..1633e89acd564 100644
--- a/clients/src/test/java/org/apache/kafka/common/protocol/types/ProtocolSerializationTest.java
+++ b/clients/src/test/java/org/apache/kafka/common/protocol/types/ProtocolSerializationTest.java
@@ -18,6 +18,7 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.fail;
 
 import java.nio.ByteBuffer;
@@ -231,6 +232,13 @@ public void testReadNegativeBytesSize() {
         }
     }
 
+    @Test
+    public void testToString() {
+        String structStr = this.struct.toString();
+        assertNotNull("Struct string should not be null.", structStr);
+        assertFalse("Struct string should not be empty.", structStr.isEmpty());
+    }
+
     private Object roundtrip(Type type, Object obj) {
         ByteBuffer buffer = ByteBuffer.allocate(type.sizeOf(obj));
         type.write(buffer, obj);