diff --git a/spring-webmvc/src/main/java/org/springframework/web/servlet/support/AbstractFlashMapManager.java b/spring-webmvc/src/main/java/org/springframework/web/servlet/support/AbstractFlashMapManager.java
index 568b4d9f96..5d1a602d2c 100644
--- a/spring-webmvc/src/main/java/org/springframework/web/servlet/support/AbstractFlashMapManager.java
+++ b/spring-webmvc/src/main/java/org/springframework/web/servlet/support/AbstractFlashMapManager.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -157,21 +157,21 @@ public abstract class AbstractFlashMapManager implements FlashMapManager {
 
 	/**
 	 * Whether the given FlashMap matches the current request.
-	 * The default implementation uses the target request path and query
-	 * parameters saved in the FlashMap.
+	 * Uses the expected request path and query parameters saved in the FlashMap.
 	 */
 	protected boolean isFlashMapForRequest(FlashMap flashMap, HttpServletRequest request) {
-		if (flashMap.getTargetRequestPath() != null) {
+		String expectedPath = flashMap.getTargetRequestPath();
+		if (expectedPath != null) {
 			String requestUri = this.urlPathHelper.getOriginatingRequestUri(request);
-			if (!requestUri.equals(flashMap.getTargetRequestPath())
-					&& !requestUri.equals(flashMap.getTargetRequestPath() + "/")) {
+			if (!requestUri.equals(expectedPath)
+					&& !requestUri.equals(expectedPath + "/")) {
 				return false;
 			}
 		}
 		MultiValueMap<String, String> targetParams = flashMap.getTargetRequestParams();
-		for (String paramName : targetParams.keySet()) {
-			for (String targetValue : targetParams.get(paramName)) {
-				if (!ObjectUtils.containsElement(request.getParameterValues(paramName), targetValue)) {
+		for (String expectedName : targetParams.keySet()) {
+			for (String expectedValue : targetParams.get(expectedName)) {
+				if (!ObjectUtils.containsElement(request.getParameterValues(expectedName), expectedValue)) {
 					return false;
 				}
 			}
@@ -219,7 +219,9 @@ public abstract class AbstractFlashMapManager implements FlashMapManager {
 	private void decodeParameters(MultiValueMap<String, String> params, HttpServletRequest request) {
 		for (String name : new ArrayList<String>(params.keySet())) {
 			for (String value : new ArrayList<String>(params.remove(name))) {
-				params.add(this.urlPathHelper.decodeRequestString(request, name), this.urlPathHelper.decodeRequestString(request, value));
+				name = this.urlPathHelper.decodeRequestString(request, name);
+				value = this.urlPathHelper.decodeRequestString(request, value);
+				params.add(name, value);
 			}
 		}
 	}
diff --git a/spring-webmvc/src/test/java/org/springframework/web/servlet/support/FlashMapManagerTests.java b/spring-webmvc/src/test/java/org/springframework/web/servlet/support/FlashMapManagerTests.java
index 94e755d814..5c763eca1c 100644
--- a/spring-webmvc/src/test/java/org/springframework/web/servlet/support/FlashMapManagerTests.java
+++ b/spring-webmvc/src/test/java/org/springframework/web/servlet/support/FlashMapManagerTests.java
@@ -30,6 +30,7 @@ import org.junit.Test;
 
 import org.springframework.mock.web.test.MockHttpServletRequest;
 import org.springframework.mock.web.test.MockHttpServletResponse;
+import org.springframework.util.MultiValueMap;
 import org.springframework.web.servlet.FlashMap;
 import org.springframework.web.util.WebUtils;
 
@@ -261,6 +262,8 @@ public class FlashMapManagerTests {
 		assertEquals("/once/only", flashMap.getTargetRequestPath());
 	}
 
+	// SPR-9657, SPR-11504
+
 	@Test
 	public void saveOutputFlashMapDecodeParameters() throws Exception {
 		this.request.setCharacterEncoding("UTF-8");
@@ -274,10 +277,9 @@ public class FlashMapManagerTests {
 		flashMap.addTargetRequestParam("%3A%2F%3F%23%5B%5D%40", "value");
 		this.flashMapManager.saveOutputFlashMap(flashMap, this.request, this.response);
 
-		assertEquals(Arrays.asList("\u0410\u0410", "\u0411\u0411", "\u0412\u0412"),
-				flashMap.getTargetRequestParams().get("key"));
-		assertEquals(Arrays.asList("value"),
-				flashMap.getTargetRequestParams().get(":/?#[]@"));
+		MultiValueMap<String,String> targetRequestParams = flashMap.getTargetRequestParams();
+		assertEquals(Arrays.asList("\u0410\u0410", "\u0411\u0411", "\u0412\u0412"), targetRequestParams.get("key"));
+		assertEquals(Arrays.asList("value"), targetRequestParams.get(":/?#[]@"));
 	}