diff --git a/src/main/java/org/springframework/data/repository/query/ReturnedType.java b/src/main/java/org/springframework/data/repository/query/ReturnedType.java
index eb44d85a32..840eff42ba 100644
--- a/src/main/java/org/springframework/data/repository/query/ReturnedType.java
+++ b/src/main/java/org/springframework/data/repository/query/ReturnedType.java
@@ -24,6 +24,9 @@
 import java.util.Map;
 import java.util.Set;
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
 import org.springframework.data.mapping.Parameter;
 import org.springframework.data.mapping.PreferredConstructor;
 import org.springframework.data.mapping.model.PreferredConstructorDiscoverer;
@@ -47,6 +50,8 @@
  */
 public abstract class ReturnedType {
 
+	private static final Log logger = LogFactory.getLog(ReturnedType.class);
+
 	private static final Map<CacheKey, ReturnedType> cache = new ConcurrentReferenceHashMap<>(32);
 
 	private final Class<?> domainType;
@@ -294,10 +299,21 @@ private List<String> detectConstructorParameterNames(Class<?> type) {
 				return Collections.emptyList();
 			}
 
-			List<String> properties = new ArrayList<>(constructor.getConstructor().getParameterCount());
+			int parameterCount = constructor.getConstructor().getParameterCount();
+			List<String> properties = new ArrayList<>(parameterCount);
 
 			for (Parameter<Object, ?> parameter : constructor.getParameters()) {
-				properties.add(parameter.getName());
+				if (parameter.getName() != null) {
+					properties.add(parameter.getName());
+				}
+			}
+
+			if (properties.isEmpty() && parameterCount > 0) {
+				if (logger.isWarnEnabled()) {
+					logger.warn(("No constructor parameter names discovered. "
+							+ "Compile the affected code with '-parameters' instead or avoid its introspection: %s")
+							.formatted(type.getName()));
+				}
 			}
 
 			return Collections.unmodifiableList(properties);
diff --git a/src/test/java/org/springframework/data/repository/query/ReturnedTypeUnitTests.java b/src/test/java/org/springframework/data/repository/query/ReturnedTypeUnitTests.java
index 4dfe80d71f..818cf09a11 100755
--- a/src/test/java/org/springframework/data/repository/query/ReturnedTypeUnitTests.java
+++ b/src/test/java/org/springframework/data/repository/query/ReturnedTypeUnitTests.java
@@ -167,6 +167,25 @@ void cachesInstancesBySourceTypes() {
 		assertThat(left).isSameAs(right);
 	}
 
+	@Test // GH-3225
+	void detectsKotlinInputProperties() {
+
+		var factory = new SpelAwareProxyProjectionFactory();
+
+		var returnedType = ReturnedType.of(SomeDataClass.class, Sample.class, factory);
+
+		assertThat(returnedType.getInputProperties()).containsExactly("firstname", "lastname");
+	}
+
+	@Test // GH-3225
+	void detectsKotlinValueClassInputProperties() {
+
+		var factory = new SpelAwareProxyProjectionFactory();
+
+		var returnedType = ReturnedType.of(SomeDataClassWithValues.class, Sample.class, factory);
+		assertThat(returnedType.getInputProperties()).containsExactly("email", "firstname", "lastname");
+	}
+
 	private static ReturnedType getReturnedType(String methodName, Class<?>... parameters) throws Exception {
 		return getQueryMethod(methodName, parameters).getResultProcessor().getReturnedType();
 	}
diff --git a/src/test/kotlin/org/springframework/data/repository/query/SomeDataClass.kt b/src/test/kotlin/org/springframework/data/repository/query/SomeDataClass.kt
new file mode 100644
index 0000000000..c4675e8ca0
--- /dev/null
+++ b/src/test/kotlin/org/springframework/data/repository/query/SomeDataClass.kt
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2025 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.data.repository.query
+
+/**
+ * @author Mark Paluch
+ */
+data class SomeDataClass(val firstname: String, val lastname: String = "Doe")
+
+@JvmInline
+value class Email(val value: String)
+
+data class SomeDataClassWithValues(
+	val email: Email,
+	val firstname: String,
+	val lastname: String = "Doe"
+)