diff --git a/spring-test/src/test/kotlin/org/springframework/test/web/reactive/server/WebTestClientKotlinTests.kt b/spring-test/src/test/kotlin/org/springframework/test/web/reactive/server/WebTestClientKotlinTests.kt
index 69353f358d1..8e22ea41bbd 100644
--- a/spring-test/src/test/kotlin/org/springframework/test/web/reactive/server/WebTestClientKotlinTests.kt
+++ b/spring-test/src/test/kotlin/org/springframework/test/web/reactive/server/WebTestClientKotlinTests.kt
@@ -1,3 +1,19 @@
+/*
+ * Copyright 2002-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package org.springframework.test.web.reactive.server
 
 import kotlinx.serialization.Serializable
@@ -34,4 +50,4 @@ class WebTestClientKotlinTests {
 		@GetMapping("test")
 		fun test(): List<Response> = listOf(Response("Hello"), Response("World"))
 	}
-}
\ No newline at end of file
+}
diff --git a/spring-web/src/main/java/org/springframework/http/codec/KotlinSerializationStringDecoder.java b/spring-web/src/main/java/org/springframework/http/codec/KotlinSerializationStringDecoder.java
index e234ca4c688..69fb226442e 100644
--- a/spring-web/src/main/java/org/springframework/http/codec/KotlinSerializationStringDecoder.java
+++ b/spring-web/src/main/java/org/springframework/http/codec/KotlinSerializationStringDecoder.java
@@ -55,7 +55,7 @@ public abstract class KotlinSerializationStringDecoder<T extends StringFormat> e
 	implements Decoder<Object> {
 
 	// String decoding needed for now, see https://github.com/Kotlin/kotlinx.serialization/issues/204 for more details
-	private final StringDecoder stringDecoder = StringDecoder.allMimeTypes(StringDecoder.DEFAULT_DELIMITERS, false);
+	protected final StringDecoder stringDecoder = StringDecoder.allMimeTypes(StringDecoder.DEFAULT_DELIMITERS, false);
 
 
 	/**
@@ -116,21 +116,23 @@ public abstract class KotlinSerializationStringDecoder<T extends StringFormat> e
 	}
 
 	@Override
-	@SuppressWarnings("unchecked")
 	public Flux<Object> decode(Publisher<DataBuffer> inputStream, ResolvableType elementType,
 			@Nullable MimeType mimeType, @Nullable Map<String, Object> hints) {
 		return Flux.defer(() -> {
 			KSerializer<Object> serializer = serializer(elementType);
-			KSerializer<Object> listSerializer = serializer(ResolvableType.forClassWithGenerics(List.class, elementType));
-			if (serializer == null || listSerializer == null) {
+			if (serializer == null) {
 				return Mono.error(new DecodingException("Could not find KSerializer for " + elementType));
 			}
 			return this.stringDecoder
 					.decode(inputStream, elementType, mimeType, hints)
-					.flatMapIterable(string -> string.startsWith("[") ?
-							(List<Object>) format().decodeFromString(listSerializer, string) :
-							List.of(format().decodeFromString(serializer, string)))
-					.onErrorMap(IllegalArgumentException.class, this::processException);
+					.handle((string, sink) -> {
+						try {
+							sink.next(format().decodeFromString(serializer, string));
+						}
+						catch (IllegalArgumentException ex) {
+							sink.error(processException(ex));
+						}
+					});
 		});
 	}
 
@@ -156,7 +158,7 @@ public abstract class KotlinSerializationStringDecoder<T extends StringFormat> e
 		});
 	}
 
-	private CodecException processException(IllegalArgumentException ex) {
+	protected CodecException processException(IllegalArgumentException ex) {
 		return new DecodingException("Decoding error: " + ex.getMessage(), ex);
 	}
 
diff --git a/spring-web/src/main/java/org/springframework/http/codec/json/KotlinSerializationJsonDecoder.java b/spring-web/src/main/java/org/springframework/http/codec/json/KotlinSerializationJsonDecoder.java
index 227f320987c..7198e1992b5 100644
--- a/spring-web/src/main/java/org/springframework/http/codec/json/KotlinSerializationJsonDecoder.java
+++ b/spring-web/src/main/java/org/springframework/http/codec/json/KotlinSerializationJsonDecoder.java
@@ -16,11 +16,22 @@
 
 package org.springframework.http.codec.json;
 
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
 import java.util.function.Predicate;
 
+import kotlinx.serialization.KSerializer;
+import kotlinx.serialization.builtins.BuiltinSerializersKt;
 import kotlinx.serialization.json.Json;
+import org.jspecify.annotations.Nullable;
+import org.reactivestreams.Publisher;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
 
 import org.springframework.core.ResolvableType;
+import org.springframework.core.codec.DecodingException;
+import org.springframework.core.io.buffer.DataBuffer;
 import org.springframework.http.MediaType;
 import org.springframework.http.codec.KotlinSerializationStringDecoder;
 import org.springframework.util.MimeType;
@@ -95,4 +106,37 @@ public class KotlinSerializationJsonDecoder extends KotlinSerializationStringDec
 		super(json, typePredicate, DEFAULT_JSON_MIME_TYPES);
 	}
 
+	@Override
+	public Flux<Object> decode(Publisher<DataBuffer> inputStream, ResolvableType elementType,
+			@Nullable MimeType mimeType, @Nullable Map<String, Object> hints) {
+		return Flux.defer(() -> {
+			KSerializer<Object> serializer = serializer(elementType);
+			if (serializer == null) {
+				return Mono.error(new DecodingException("Could not find KSerializer for " + elementType));
+			}
+			return this.stringDecoder
+					.decode(inputStream, elementType, mimeType, hints)
+					.switchOnFirst((signal, flux) -> {
+						if (signal.hasValue()) {
+							String value = Objects.requireNonNull(signal.get());
+							if (value.stripLeading().startsWith("[") && !List.class.isAssignableFrom(elementType.toClass())) {
+								KSerializer<List<Object>> listSerializer = BuiltinSerializersKt.ListSerializer(serializer);
+								return flux
+										.flatMapIterable(string -> format().decodeFromString(listSerializer, string))
+										.onErrorMap(IllegalArgumentException.class, this::processException);
+							}
+							return flux.handle((string, sink) -> {
+								try {
+									sink.next(format().decodeFromString(serializer, string));
+								}
+								catch (IllegalArgumentException ex) {
+									sink.error(processException(ex));
+								}
+							});
+						}
+						return flux;
+					});
+		});
+	}
+
 }
diff --git a/spring-web/src/test/kotlin/org/springframework/http/codec/json/KotlinSerializationJsonDecoderTests.kt b/spring-web/src/test/kotlin/org/springframework/http/codec/json/KotlinSerializationJsonDecoderTests.kt
index f2e6a93800f..ce53bb9a0ac 100644
--- a/spring-web/src/test/kotlin/org/springframework/http/codec/json/KotlinSerializationJsonDecoderTests.kt
+++ b/spring-web/src/test/kotlin/org/springframework/http/codec/json/KotlinSerializationJsonDecoderTests.kt
@@ -211,6 +211,20 @@ class KotlinSerializationJsonDecoderTests : AbstractDecoderTests<KotlinSerializa
 		}, null, null)
 	}
 
+	@Test
+	fun decodeJsonArrayToFluxOfList() {
+		val input = Flux.concat(
+			stringBuffer("[{\"bar\":\"b1\",\"foo\":\"f1\"},{\"bar\":\"b2\",\"foo\":\"f2\"}]\n"),
+			stringBuffer("[{\"bar\":\"b3\",\"foo\":\"f3\"},{\"bar\":\"b4\",\"foo\":\"f4\"}]"))
+
+		testDecodeAll(input, ResolvableType.forClassWithGenerics(List::class.java, Pojo::class.java), {
+			it.expectNext(listOf(Pojo("f1", "b1"),Pojo("f2", "b2")))
+				.expectNext(listOf(Pojo("f3", "b3"),Pojo("f4", "b4")))
+				.expectComplete()
+				.verify()
+		}, null, null)
+	}
+
 	@Test
 	override fun decodeToMono() {
 		val input = Flux.concat(