diff --git a/spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/support/ServerWebExchangeUtils.java b/spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/support/ServerWebExchangeUtils.java
index ca90c619..52f420ab 100644
--- a/spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/support/ServerWebExchangeUtils.java
+++ b/spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/support/ServerWebExchangeUtils.java
@@ -214,13 +214,16 @@ public final class ServerWebExchangeUtils {
 		boolean encoded = (uri.getRawQuery() != null && uri.getRawQuery().contains("%"))
 				|| (uri.getRawPath() != null && uri.getRawPath().contains("%"));
 
-		// Verify if it is really fully encoded. Treat partial encoded as uncoded.
+		// Verify if it is really fully encoded. Treat partial encoded as unencoded.
 		if (encoded) {
 			try {
 				UriComponentsBuilder.fromUri(uri).build(true);
 				return true;
 			}
 			catch (IllegalArgumentException ignore) {
+				if (log.isTraceEnabled()) {
+					log.trace("Error in containsEncodedParts", ignore);
+				}
 			}
 
 			return false;
diff --git a/spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/filter/RouteToRequestUrlFilterTests.java b/spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/filter/RouteToRequestUrlFilterTests.java
index e9b09318..a63f0bdc 100644
--- a/spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/filter/RouteToRequestUrlFilterTests.java
+++ b/spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/filter/RouteToRequestUrlFilterTests.java
@@ -132,10 +132,12 @@ public class RouteToRequestUrlFilterTests {
 		ServerWebExchange webExchange = testFilter(request, "http://myhost");
 		URI uri = webExchange.getRequiredAttribute(GATEWAY_REQUEST_URL_ATTR);
 		assertThat(uri).hasScheme("http").hasHost("myhost")
-				.hasParameter("key[]", "test= key").hasParameter("start", "1533108081");
+				// since https://github.com/joel-costigliola/assertj-core/issues/1699
+				// assertj uses raw query
+				.hasParameter("key[]", "test=%20key").hasParameter("start", "1533108081");
 
 		// prove that it is double encoded since partial encoded uri is treated as
-		// uncoded.
+		// unencoded.
 		assertThat(uri.getRawQuery()).isEqualTo("key[]=test=%2520key&start=1533108081");
 	}