diff --git a/spring-cloud-gateway-server-webmvc/src/main/java/org/springframework/cloud/gateway/server/mvc/handler/ProxyExchangeHandlerFunction.java b/spring-cloud-gateway-server-webmvc/src/main/java/org/springframework/cloud/gateway/server/mvc/handler/ProxyExchangeHandlerFunction.java
index 5116808ed..f262ffc1f 100644
--- a/spring-cloud-gateway-server-webmvc/src/main/java/org/springframework/cloud/gateway/server/mvc/handler/ProxyExchangeHandlerFunction.java
+++ b/spring-cloud-gateway-server-webmvc/src/main/java/org/springframework/cloud/gateway/server/mvc/handler/ProxyExchangeHandlerFunction.java
@@ -98,6 +98,10 @@ public ServerResponse handle(ServerRequest serverRequest) {
 				.replaceQueryParams(params)
 				.build(true)
 				.toUri();
+		String rawQuery = serverRequest.uri().getRawQuery();
+		if (hasValuelessQueryParameter(rawQuery)) {
+			url = UriComponentsBuilder.fromUri(url).replaceQuery(rawQuery).build(true).toUri();
+		}
 		// @formatter:on
 
 		HttpHeaders filteredRequestHeaders = filterHeaders(this.requestHttpHeadersFilters,
@@ -139,6 +143,18 @@ private <REQUEST_OR_RESPONSE> HttpHeaders filterHeaders(@Nullable List<?> filter
 		return filtered;
 	}
 
+	private boolean hasValuelessQueryParameter(@Nullable String rawQuery) {
+		if (rawQuery == null || rawQuery.isEmpty()) {
+			return false;
+		}
+		for (String pair : rawQuery.split("&")) {
+			if (!pair.isEmpty() && pair.indexOf('=') < 0) {
+				return true;
+			}
+		}
+		return false;
+	}
+
 	public interface URIResolver extends Function<ServerRequest, URI> {
 
 	}
diff --git a/spring-cloud-gateway-server-webmvc/src/test/java/org/springframework/cloud/gateway/server/mvc/handler/ProxyExchangeHandlerFunctionTest.java b/spring-cloud-gateway-server-webmvc/src/test/java/org/springframework/cloud/gateway/server/mvc/handler/ProxyExchangeHandlerFunctionTest.java
index 5d1313cae..212e73ee7 100644
--- a/spring-cloud-gateway-server-webmvc/src/test/java/org/springframework/cloud/gateway/server/mvc/handler/ProxyExchangeHandlerFunctionTest.java
+++ b/spring-cloud-gateway-server-webmvc/src/test/java/org/springframework/cloud/gateway/server/mvc/handler/ProxyExchangeHandlerFunctionTest.java
@@ -103,7 +103,7 @@ public Stream<ResponseHttpHeadersFilter> orderedStream() {
 		function.onApplicationEvent(null);
 
 		MockHttpServletRequest servletRequest = MockMvcRequestBuilders
-			.get("http://localhost/é?foo=value1 value2&bar=value3=&qux=value4+")
+			.get("http://localhost/é?foo=value1 value2&bar=value3=&qux=value4+&flag&next=1")
 			.buildRequest(null);
 		servletRequest.setAttribute(MvcUtils.GATEWAY_REQUEST_URL_ATTR, URI.create("http://localhost:8080"));
 		ServerRequest request = ServerRequest.create(servletRequest, Collections.emptyList());
@@ -112,11 +112,8 @@ public Stream<ResponseHttpHeadersFilter> orderedStream() {
 
 		URI uri = proxyExchange.getRequest().getUri();
 
-		assertThat(uri).hasToString("http://localhost:8080/%C3%A9?foo=value1%20value2&bar=value3%3D&qux=value4%2B")
-			.hasPath("/é")
-			.hasParameter("foo", "value1 value2")
-			.hasParameter("bar", "value3=")
-			.hasParameter("qux", "value4+");
+		assertThat(uri).hasToString("http://localhost:8080/%C3%A9?foo=value1%20value2&bar=value3=&qux=value4+&flag&next=1")
+			.hasPath("/é");
 	}
 
 	private class TestProxyExchange extends AbstractProxyExchange {