diff --git a/org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/mvc/annotation/ServletAnnotationControllerTests.java b/org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/mvc/annotation/ServletAnnotationControllerTests.java
index 38547d30546..444d2ba9162 100644
--- a/org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/mvc/annotation/ServletAnnotationControllerTests.java
+++ b/org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/mvc/annotation/ServletAnnotationControllerTests.java
@@ -16,6 +16,7 @@
 
 package org.springframework.web.servlet.mvc.annotation;
 
+import java.beans.PropertyEditorSupport;
 import java.io.IOException;
 import java.io.Serializable;
 import java.io.UnsupportedEncodingException;
@@ -1473,6 +1474,22 @@ public class ServletAnnotationControllerTests {
 		assertEquals("templatePath", response.getContentAsString());
 	}
 
+	/*
+	 * See SPR-6021
+	 */
+	@Test
+	public void customMapEditor() throws Exception {
+		initServlet(CustomMapEditorController.class);
+
+		MockHttpServletRequest request = new MockHttpServletRequest("GET", "/handle");
+		request.addParameter("map", "bar");
+		MockHttpServletResponse response = new MockHttpServletResponse();
+
+		servlet.service(request, response);
+
+		assertEquals("test-{foo=bar}", response.getContentAsString());
+	}
+
 	/*
 	 * Controllers
 	 */
@@ -2538,5 +2555,36 @@ public class ServletAnnotationControllerTests {
 		}
 	}
 
+	@Controller
+	public static class CustomMapEditorController {
+
+		@InitBinder
+		public void initBinder(WebDataBinder binder) {
+			binder.initBeanPropertyAccess();
+			binder.registerCustomEditor(Map.class, new CustomMapEditor());
+		}
+
+		@RequestMapping("/handle")
+		public void handle(@RequestParam("map") Map map, Writer writer) throws IOException {
+			writer.write("test-" + map);
+		}
+
+
+	}
+
+	public static class CustomMapEditor extends PropertyEditorSupport {
+
+		@Override
+		public void setAsText(String text) throws IllegalArgumentException {
+			if (StringUtils.hasText(text)) {
+				setValue(Collections.singletonMap("foo", text));
+			}
+			else {
+				setValue(null);
+			}
+		}
+
+	}
+
 
 }
diff --git a/org.springframework.web/src/main/java/org/springframework/web/bind/annotation/support/HandlerMethodInvoker.java b/org.springframework.web/src/main/java/org/springframework/web/bind/annotation/support/HandlerMethodInvoker.java
index 7475d18036a..a3bedef15fc 100644
--- a/org.springframework.web/src/main/java/org/springframework/web/bind/annotation/support/HandlerMethodInvoker.java
+++ b/org.springframework.web/src/main/java/org/springframework/web/bind/annotation/support/HandlerMethodInvoker.java
@@ -419,7 +419,7 @@ public class HandlerMethodInvoker {
 			throws Exception {
 
 		Class<?> paramType = methodParam.getParameterType();
-		if (Map.class.isAssignableFrom(paramType)) {
+		if (Map.class.isAssignableFrom(paramType) && paramName.length() == 0) {
 			return resolveRequestParamMap((Class<? extends Map>) paramType, webRequest);
 		}
 		if (paramName.length() == 0) {