diff --git a/build.gradle b/build.gradle
index c7a5cd1..bd52878 100644
--- a/build.gradle
+++ b/build.gradle
@@ -2,7 +2,7 @@
 plugins {
     id "org.sonarqube" version "2.6.1"
     id "io.codearte.nexus-staging" version "0.11.0"
-    id "com.github.spotbugs" version "1.6.9"
+    id "com.github.spotbugs" version "2.0.0"
     id "org.xbib.gradle.plugin.asciidoctor" version "1.5.6.0.1"
 }
 
@@ -10,7 +10,6 @@ subprojects {
 
     apply plugin: 'java'
     apply plugin: 'maven'
-    apply plugin: 'signing'
     apply plugin: 'checkstyle'
     apply plugin: 'com.github.spotbugs'
     apply plugin: 'pmd'
@@ -63,7 +62,7 @@ subprojects {
         systemProperty 'java.net.preferIPv6Addresses', 'true'
         failFast = false
         testLogging {
-            events 'PASSED', 'FAILED', 'SKIPPED'
+            events 'STARTED', 'PASSED', 'FAILED', 'SKIPPED'
         }
         afterSuite { desc, result ->
             if (!desc.parent) {
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index b005719..8a3402a 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Tue Apr 16 23:50:27 CEST 2019
+#Wed Aug 07 23:28:18 CEST 2019
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.3.1-all.zip
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.3-all.zip
+zipStoreBase=GRADLE_USER_HOME
diff --git a/net-url/src/main/java/org/xbib/net/URL.java b/net-url/src/main/java/org/xbib/net/URL.java
index 0c089b1..d72c0da 100755
--- a/net-url/src/main/java/org/xbib/net/URL.java
+++ b/net-url/src/main/java/org/xbib/net/URL.java
@@ -500,7 +500,7 @@ public class URL implements Comparable<URL> {
     }
 
     public URL normalize() {
-        return scheme.normalize(this);
+        return scheme != null ? scheme.normalize(this) : this;
     }
 
     public String toExternalForm() {
diff --git a/net-url/src/test/java/org/xbib/net/URLResolverTest.java b/net-url/src/test/java/org/xbib/net/URLResolverTest.java
index dfd9a2a..28c50d7 100644
--- a/net-url/src/test/java/org/xbib/net/URLResolverTest.java
+++ b/net-url/src/test/java/org/xbib/net/URLResolverTest.java
@@ -44,7 +44,7 @@ class URLResolverTest {
         String pathSpec = "foobar/";
         String index = "index.html";
         String queryString = "a=b";
-        URL url = base.resolve(pathSpec).resolve(index).newBuilder().query(queryString).build().normalize();
+        URL url = base.resolve(pathSpec).resolve(index).mutator().query(queryString).build().normalize();
         assertEquals("http://example:8080/foobar/index.html?a=b", url.toString());
     }