diff --git a/spring-webflow/src/main/java/org/springframework/webflow/action/ActionResultExposer.java b/spring-webflow/src/main/java/org/springframework/webflow/action/ActionResultExposer.java
index 8c8eeade..0fd1d231 100644
--- a/spring-webflow/src/main/java/org/springframework/webflow/action/ActionResultExposer.java
+++ b/spring-webflow/src/main/java/org/springframework/webflow/action/ActionResultExposer.java
@@ -57,12 +57,12 @@ public class ActionResultExposer implements Serializable {
 	public ActionResultExposer(Expression resultExpression, Class expectedResultType,
 			ConversionService conversionService) {
 		Assert.notNull(resultExpression, "The result expression is required");
+		if (expectedResultType != null) {
+			Assert.notNull(conversionService, "A conversionService is required with an expectedResultType");
+		}
 		this.resultExpression = resultExpression;
 		this.expectedResultType = expectedResultType;
-		if (this.expectedResultType != null) {
-			Assert.notNull(conversionService, "A conversionService is required with an expectedResultType");
-			this.conversionService = conversionService;
-		}
+		this.conversionService = conversionService;
 	}
 
 	/**
@@ -93,10 +93,11 @@ public class ActionResultExposer implements Serializable {
 	 * @param value the raw value to be converted
 	 */
 	private Object applyTypeConversion(Object value) {
-		if (expectedResultType == null) {
+		if (value == null || expectedResultType == null) {
 			return value;
+		} else {
+			return conversionService.getConversionExecutor(value.getClass(), expectedResultType).execute(value);
 		}
-		return conversionService.getConversionExecutor(value.getClass(), expectedResultType).execute(value);
 	}
 
 	public String toString() {
diff --git a/spring-webflow/src/test/java/org/springframework/webflow/action/ActionResultExposerTests.java b/spring-webflow/src/test/java/org/springframework/webflow/action/ActionResultExposerTests.java
index 6d568aee..43b6fbcb 100644
--- a/spring-webflow/src/test/java/org/springframework/webflow/action/ActionResultExposerTests.java
+++ b/spring-webflow/src/test/java/org/springframework/webflow/action/ActionResultExposerTests.java
@@ -8,7 +8,7 @@ import org.springframework.webflow.test.MockRequestContext;
 
 public class ActionResultExposerTests extends TestCase {
 
-	public void testEvaluateExpressionNullResult() throws Exception {
+	public void testEvaluateExpressionResult() throws Exception {
 		StaticExpression resultExpression = new StaticExpression("");
 		ActionResultExposer exposer = new ActionResultExposer(resultExpression, null, null);
 		MockRequestContext context = new MockRequestContext();
@@ -16,6 +16,14 @@ public class ActionResultExposerTests extends TestCase {
 		assertEquals("foo", resultExpression.getValue(null));
 	}
 
+	public void testEvaluateExpressionNullResult() throws Exception {
+		StaticExpression resultExpression = new StaticExpression("");
+		ActionResultExposer exposer = new ActionResultExposer(resultExpression, null, null);
+		MockRequestContext context = new MockRequestContext();
+		exposer.exposeResult(null, context);
+		assertEquals(null, resultExpression.getValue(null));
+	}
+
 	public void testEvaluateExpressionResultExposerWithTypeConversion() throws Exception {
 		StaticExpression resultExpression = new StaticExpression("");
 		ActionResultExposer exposer = new ActionResultExposer(resultExpression, Integer.class,