WebDAV Wagon does not encode umlauts

I am not able to use wagon with files containing umlauts in their filename.
It seems like the url is not correctly encoded. Please have a look at the following stack trace:

org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-site-plugin:3.4:deploy (default-deploy) on project solar-documentation: Execution default-deploy of goal org.apache.maven.plugins:maven-site-plugin:3.4:deploy failed: Invalid uri 'http://data/bibliothek/solar-documentation/current/solar-documentation/referenz/_speichern_löschen.html': escaped absolute path not valid
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:225)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:320)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:537)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:141)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Caused by: org.apache.maven.plugin.PluginExecutionException: Execution default-deploy of goal org.apache.maven.plugins:maven-site-plugin:3.4:deploy failed: Invalid uri 'http://data/bibliothek/solar-documentation/current/solar-documentation/referenz/_speichern_löschen.html': escaped absolute path not valid
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:110)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209)
... 19 more
Caused by: java.lang.IllegalArgumentException: Invalid uri 'http://data/bibliothek/solar-documentation/current/solar-documentation/referenz/_speichern_löschen.html': escaped absolute path not valid
at org.apache.commons.httpclient.HttpMethodBase.<init>(HttpMethodBase.java:222)
at org.apache.commons.httpclient.methods.ExpectContinueMethod.<init>(ExpectContinueMethod.java:93)
at org.apache.commons.httpclient.methods.EntityEnclosingMethod.<init>(EntityEnclosingMethod.java:119)
at org.apache.commons.httpclient.methods.PutMethod.<init>(PutMethod.java:76)
at org.apache.maven.wagon.providers.webdav.AbstractHttpClientWagon.put(AbstractHttpClientWagon.java:356)
at org.apache.maven.wagon.providers.webdav.AbstractHttpClientWagon.put(AbstractHttpClientWagon.java:324)
at org.apache.maven.wagon.providers.webdav.AbstractHttpClientWagon.put(AbstractHttpClientWagon.java:301)
at org.apache.maven.wagon.providers.webdav.WebDavWagon.put(WebDavWagon.java:326)
at org.apache.maven.wagon.providers.webdav.WebDavWagon.putDirectory(WebDavWagon.java:187)
at org.apache.maven.wagon.providers.webdav.WebDavWagon.putDirectory(WebDavWagon.java:181)
at org.apache.maven.plugins.site.deploy.AbstractDeployMojo.push(AbstractDeployMojo.java:441)
at org.apache.maven.plugins.site.deploy.AbstractDeployMojo.deploy(AbstractDeployMojo.java:323)
at org.apache.maven.plugins.site.deploy.AbstractDeployMojo.deployTo(AbstractDeployMojo.java:284)
at org.apache.maven.plugins.site.deploy.AbstractDeployMojo.execute(AbstractDeployMojo.java:166)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
... 20 more