diff --git a/src/main/java/org/springframework/data/repository/query/ResultProcessor.java b/src/main/java/org/springframework/data/repository/query/ResultProcessor.java
index 55b8ebad0..1cc382141 100644
--- a/src/main/java/org/springframework/data/repository/query/ResultProcessor.java
+++ b/src/main/java/org/springframework/data/repository/query/ResultProcessor.java
@@ -23,7 +23,6 @@ import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Optional;
 import java.util.stream.Stream;
 
 import org.springframework.core.CollectionFactory;
@@ -84,12 +83,14 @@ public class ResultProcessor {
 	/**
 	 * Returns a new {@link ResultProcessor} with a new projection type obtained from the given {@link ParameterAccessor}.
 	 * 
-	 * @param accessor can be {@literal null}.
+	 * @param accessor must not be {@literal null}.
 	 * @return
 	 */
-	public ResultProcessor withDynamicProjection(Optional<ParameterAccessor> accessor) {
+	public ResultProcessor withDynamicProjection(ParameterAccessor accessor) {
 
-		return accessor.flatMap(ParameterAccessor::getDynamicProjection)//
+		Assert.notNull(accessor, "Parameter accessor must not be null!");
+
+		return accessor.getDynamicProjection()//
 				.map(it -> new ResultProcessor(method, factory, it))//
 				.orElse(this);
 	}
diff --git a/src/test/java/org/springframework/data/repository/query/ResultProcessorUnitTests.java b/src/test/java/org/springframework/data/repository/query/ResultProcessorUnitTests.java
index dc23a3bed..daf8a02e8 100755
--- a/src/test/java/org/springframework/data/repository/query/ResultProcessorUnitTests.java
+++ b/src/test/java/org/springframework/data/repository/query/ResultProcessorUnitTests.java
@@ -25,7 +25,6 @@ import rx.Single;
 
 import java.lang.reflect.Method;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
@@ -144,12 +143,11 @@ public class ResultProcessorUnitTests {
 		ParameterAccessor accessor = mock(ParameterAccessor.class);
 
 		ResultProcessor factory = getProcessor("findOneDynamic", Class.class);
-		assertThat(factory.withDynamicProjection(Optional.empty())).isEqualTo(factory);
-		assertThat(factory.withDynamicProjection(Optional.of(accessor))).isEqualTo(factory);
+		assertThat(factory.withDynamicProjection(accessor)).isEqualTo(factory);
 
 		doReturn(Optional.of(SampleProjection.class)).when(accessor).getDynamicProjection();
 
-		ResultProcessor processor = factory.withDynamicProjection(Optional.of(accessor));
+		ResultProcessor processor = factory.withDynamicProjection(accessor);
 		assertThat(processor.getReturnedType().getReturnedType()).isEqualTo(SampleProjection.class);
 	}