diff --git a/src/main/java/edu/kit/scc/dem/wapsrv/model/formats/JsonLdFormatter.java b/src/main/java/edu/kit/scc/dem/wapsrv/model/formats/JsonLdFormatter.java
index 106ab16..e3b5164 100644
--- a/src/main/java/edu/kit/scc/dem/wapsrv/model/formats/JsonLdFormatter.java
+++ b/src/main/java/edu/kit/scc/dem/wapsrv/model/formats/JsonLdFormatter.java
@@ -1,8 +1,8 @@
 package edu.kit.scc.dem.wapsrv.model.formats;
 
 import java.io.IOException;
-import java.net.MalformedURLException;
-import java.net.URL;
+import java.net.URI;
+import java.net.URISyntaxException;
 import java.util.*;
 import java.util.regex.Pattern;
 import org.apache.commons.collections4.map.ListOrderedMap;
@@ -40,11 +40,11 @@ public final class JsonLdFormatter extends AbstractFormatter {
     /**
      * The default JSON-LD Profile
      */
-    public static final URL DEFAULT_PROFILE = makeUrl("http://www.w3.org/ns/anno.jsonld");
+    public static final URI DEFAULT_PROFILE = makeUri("http://www.w3.org/ns/anno.jsonld");
     /**
      * The LDP profile for containers
      */
-    public static final URL LDP_PROFILE = makeUrl("http://www.w3.org/ns/ldp.jsonld");
+    public static final URI LDP_PROFILE = makeUri("http://www.w3.org/ns/ldp.jsonld");
     /**
      * The string identifying JSON-LD
      */
@@ -52,7 +52,7 @@ public final class JsonLdFormatter extends AbstractFormatter {
     /**
      * The set of used profiles
      */
-    private final Set<URL> profiles = new HashSet<>();
+    private final Set<URI> profiles = new HashSet<>();
     /**
      * The profile registry
      */
@@ -76,10 +76,10 @@ public JsonLdFormatter() {
      * @param urlString The String to generate a URL from
      * @return The generated URL Object
      */
-    private static URL makeUrl(String urlString) {
+    private static URI makeUri(String urlString) {
         try {
-            return new java.net.URL(urlString);
-        } catch (java.net.MalformedURLException e) {
+            return new URI(urlString);
+        } catch (URISyntaxException e) {
             LoggerFactory.getLogger(ContentNegotiator.class).error("DEFAULT_PROFILE is an invalid URL : " + urlString);
             return null;
         }
@@ -210,7 +210,7 @@ private String applyProfiles(String jsonLd, String frameString) {
                 jsonObject = JsonLdProcessor.frame(jsonObject, frameObject, options);
 
                 // Collect contexts from profiles
-                for (URL url : profiles) {
+                for (URI url : profiles) {
                     contexts.add(url.toString());
                 }
 
@@ -228,7 +228,7 @@ private String applyProfiles(String jsonLd, String frameString) {
                     }
                 }
             }
-            for (URL url : profiles) {
+            for (URI url : profiles) {
                 contexts.add(url.toString());
             }
             contexts = deduplicateContexts(contexts);
@@ -335,7 +335,7 @@ public void setAcceptPart(String profilesRaw, Type type) {
                 for (String profile : profiles) {
                     String trimmedProfile = profile.trim();
                     try {
-                        URL url = new URL(trimmedProfile);
+                        URI url = new URI(trimmedProfile);
                         // At least a valid url, but is it locally cached?
                         // We do not support uncached profiles. Inform the registry we need it cached.
                         if (profileRegistry.cacheProfile(url)) {
@@ -344,7 +344,7 @@ public void setAcceptPart(String profilesRaw, Type type) {
                         } else {
                             logger.debug("Skipping not reachable profile : " + url);
                         }
-                    } catch (MalformedURLException e) {
+                    } catch (URISyntaxException e) {
                         // not a valid url, this is an error
                         logger.error("Malformed URL in JSON-LD Profile : " + trimmedProfile);
                     }
@@ -357,15 +357,12 @@ public void setAcceptPart(String profilesRaw, Type type) {
         // The default profiles are always added if no accept header is given at all
         if (profilesRaw == null || WapServerConfig.getInstance().shouldAlwaysAddDefaultProfilesToJsonLdRequests()) {
             switch (type) {
+                //TODO: check if this behaviour is working as intended
                 case CONTAINER:
-                    if (!profiles.contains(LDP_PROFILE)) {
-                        profiles.add(LDP_PROFILE);
-                    }
+                    profiles.add(LDP_PROFILE);
                 case ANNOTATION:
                 case PAGE:
-                    if (!profiles.contains(DEFAULT_PROFILE)) {
-                        profiles.add(DEFAULT_PROFILE);
-                    }
+                    profiles.add(DEFAULT_PROFILE);
                     break;
                 default:
                 // Unknown type ? do nothing because profile negotiation can be ignored by the server
@@ -394,7 +391,7 @@ public String getContentType() {
             return getFormatString();
         }
         StringBuilder profileString = new StringBuilder();
-        for (URL url : profiles) {
+        for (URI url : profiles) {
             String context = url.toString();
             if (!profileString.isEmpty()) {
                 profileString.append(" ");
diff --git a/src/main/java/edu/kit/scc/dem/wapsrv/model/formats/JsonLdProfileRegistry.java b/src/main/java/edu/kit/scc/dem/wapsrv/model/formats/JsonLdProfileRegistry.java
index 02a1ac1..d5b7fe0 100644
--- a/src/main/java/edu/kit/scc/dem/wapsrv/model/formats/JsonLdProfileRegistry.java
+++ b/src/main/java/edu/kit/scc/dem/wapsrv/model/formats/JsonLdProfileRegistry.java
@@ -6,11 +6,7 @@
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
-import java.net.HttpURLConnection;
-import java.net.InetSocketAddress;
-import java.net.MalformedURLException;
-import java.net.Proxy;
-import java.net.URL;
+import java.net.*;
 import java.nio.file.Files;
 import java.util.HashSet;
 import java.util.Hashtable;
@@ -33,7 +29,6 @@
 import edu.kit.scc.dem.wapsrv.exceptions.FormatException;
 import edu.kit.scc.dem.wapsrv.exceptions.InternalServerException;
 import edu.kit.scc.dem.wapsrv.model.FormattableObject.Type;
-import java.net.URI;
 
 /**
  * Central registry for JSON-LD profiles. It manages a local in memory profile
@@ -92,19 +87,19 @@ public final class JsonLdProfileRegistry {
      * The set of profiles loaded and cached. This set is dynamically populated
      * on first usage.
      */
-    private final Set<URL> cachedProfiles = new HashSet<URL>();
+    private final Set<URI> cachedProfiles = new HashSet<>();
     /**
      * The last times individual profiles have been updated
      */
-    private final Map<URL, Long> lastUpdateTimes = new Hashtable<URL, Long>();
+    private final Map<URI, Long> lastUpdateTimes = new Hashtable<>();
     /**
      * The number individual profiles have had update failures
      */
-    private final Map<URL, Integer> profile2failures = new Hashtable<URL, Integer>();
+    private final Map<URI, Integer> profile2failures = new Hashtable<>();
     /**
      * The last times individual profiles have had update failures
      */
-    private final Map<URL, Long> profile2failureTimes = new Hashtable<URL, Long>();
+    private final Map<URI, Long> profile2failureTimes = new Hashtable<>();
     /**
      * The frames needed for specific types
      */
@@ -258,10 +253,10 @@ private void updateProfiles() {
         for (Object key : profilesDatabase.keySet()) {
             final String filename = (String) key;
             final String urlString = profilesDatabase.getProperty(filename);
-            URL url = null;
+            URI url = null;
             try {
-                url = new URL(urlString);
-            } catch (MalformedURLException e) {
+                url = new URI(urlString);
+            } catch (URISyntaxException e) {
                 logger.warn("Invalid profile url, skipping it : " + urlString);
                 continue;
             }
@@ -354,8 +349,9 @@ private void updateProfiles() {
         setJsonLdOptions(jsonLdOptions);
     }
 
-    private boolean download(File destinationFile, URL srcUrl) {
+    private boolean download(File destinationFile, URI srcUri) {
         try {
+            URL srcUrl = srcUri.toURL();
             Proxy proxy = getProxy(srcUrl);
             HttpURLConnection httpConn
                     = (HttpURLConnection) (proxy == null ? srcUrl.openConnection() : srcUrl.openConnection(proxy));
@@ -446,10 +442,10 @@ private Proxy getProxy(URL srcUrl) {
      * @param url The URL to test
      * @return True if cached, false otherwise
      */
-    public boolean isCachedProfile(URL url) {
+    public boolean isCachedProfile(URI url) {
         blockUntilInitialized();
         // always check for http and https. The file is the same, no need to distinguish
-        URL complementaryUrl = toComplementaryUrl(url);
+        URI complementaryUrl = toComplementaryUrl(url);
         return cachedProfiles.contains(url) || cachedProfiles.contains(complementaryUrl);
     }
 
@@ -573,10 +569,10 @@ private void updateJsonLdOptions(JsonLdOptions jsonLdOptions) {
         for (Object filenameObject : profilesDatabase.keySet()) {
             final String filename = (String) filenameObject;
             final String urlString = profilesDatabase.getProperty(filename);
-            URL url = null;
+            URI url = null;
             try {
-                url = new URL(urlString);
-            } catch (MalformedURLException e) {
+                url = new URI(urlString);
+            } catch (URISyntaxException e) {
                 logger.warn("Invalid profile url, skipping it : " + urlString);
                 continue;
             }
@@ -634,14 +630,14 @@ private String toComplementaryUrl(String urlString) {
      * @param url The url to convert
      * @return The converted url
      */
-    private URL toComplementaryUrl(URL url) {
+    private URI toComplementaryUrl(URI url) {
         if (url == null) {
             return null;
         }
         String compString = toComplementaryUrl(url.toString());
         try {
-            return new URL(compString);
-        } catch (MalformedURLException e) {
+            return new URI(compString);
+        } catch (URISyntaxException e) {
             // should not happen
             logger.warn("could not complement url, this should not happen : " + url);
             // return the unswitched url as fallback
@@ -658,17 +654,17 @@ private URL toComplementaryUrl(URL url) {
      * @param url The URL to cache
      * @return True if already cached or caching was successful, false otherwise
      */
-    public boolean cacheProfile(URL url) {
+    public boolean cacheProfile(URI url) {
         if (url == null) {
             return false;
         }
         blockUntilInitialized();
         synchronized (cachedProfiles) {
-            for (URL urlRegistered : cachedProfiles) {
+            for (URI urlRegistered : cachedProfiles) {
                 if (url.equals(urlRegistered)) {
                     return true;
                 }
-                URL complementaryUrl = toComplementaryUrl(urlRegistered);
+                URI complementaryUrl = toComplementaryUrl(urlRegistered);
                 if (url.equals(complementaryUrl)) {
                     return true;
                 }
@@ -681,8 +677,8 @@ public boolean cacheProfile(URL url) {
         synchronized (updateLock) {
             final String urlString = url.toString();
             final File profileFile = new File(profileFolder, getFilename(url));
-            URL urlHttp = null;
-            URL urlHttps = null;
+            URI urlHttp = null;
+            URI urlHttps = null;
             if (url.toString().toLowerCase().startsWith("https:")) {
                 urlHttps = url;
                 urlHttp = toComplementaryUrl(url);
@@ -719,7 +715,7 @@ public boolean cacheProfile(URL url) {
         }
     }
 
-    private String getFilename(URL url) {
+    private String getFilename(URI url) {
         // We use the path part and replace / with _
         return url.getPath().replaceAll(Pattern.quote("/"), "_");
     }
@@ -731,7 +727,7 @@ private String getFilename(URL url) {
      * @param url The url to get the update time from
      * @return the last update time, -1 if never updated (=not cached yet)
      */
-    protected long getLastUpdateTime(URL url) {
+    protected long getLastUpdateTime(URI url) {
         blockUntilInitialized();
         Long lastTime = lastUpdateTimes.get(url);
         return lastTime == null ? -1 : lastTime;
diff --git a/src/test/java/edu/kit/scc/dem/wapsrv/model/formats/JsonLdProfileRegistryTest.java b/src/test/java/edu/kit/scc/dem/wapsrv/model/formats/JsonLdProfileRegistryTest.java
index f5774c3..b6ce03d 100644
--- a/src/test/java/edu/kit/scc/dem/wapsrv/model/formats/JsonLdProfileRegistryTest.java
+++ b/src/test/java/edu/kit/scc/dem/wapsrv/model/formats/JsonLdProfileRegistryTest.java
@@ -4,8 +4,8 @@
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
-import java.net.MalformedURLException;
-import java.net.URL;
+import java.net.URI;
+import java.net.URISyntaxException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Properties;
@@ -150,28 +150,28 @@ private void initTestFolder() {
         }
     }
 
-    private URL getAnnoProfileUrl() {
+    private URI getAnnoProfileUrl() {
         try {
-            return new URL(ANNO_URL_STRING);
-        } catch (MalformedURLException e) {
+            return new URI(ANNO_URL_STRING);
+        } catch (URISyntaxException e) {
             fail("Internal error, invalid profile url " + e.getMessage());
             return null;
         }
     }
 
-    private URL getLdpProfileUrl() {
+    private URI getLdpProfileUrl() {
         try {
-            return new URL(LDP_URL_STRING);
-        } catch (MalformedURLException e) {
+            return new URI(LDP_URL_STRING);
+        } catch (URISyntaxException e) {
             fail("Internal error, invalid profile url " + e.getMessage());
             return null;
         }
     }
 
-    private URL getAsProfileUrl() {
+    private URI getAsProfileUrl() {
         try {
-            return new URL(AS_URL_STRING);
-        } catch (MalformedURLException e) {
+            return new URI(AS_URL_STRING);
+        } catch (URISyntaxException e) {
             fail("Internal error, invalid profile url " + e.getMessage());
             return null;
         }
@@ -192,7 +192,7 @@ private void updateSystemProperty(String value, String key) {
     @Test
     final void testCacheUpdateWorks() {
         JsonLdProfileRegistry instance = getJsonLdProfileRegistry();
-        URL profileUrl = getAnnoProfileUrl();
+        URI profileUrl = getAnnoProfileUrl();
         long actualTime = instance.getLastUpdateTime(profileUrl);
         if (actualTime < 0) {
             fail("Profile not existent for cache update test :(");
@@ -220,7 +220,7 @@ final void testCacheUpdateWorks() {
     final void testCacheUpdateDelayWorks() {
         System.setProperty(JsonLdProfileRegistry.DISABLED_UPDATER_PROPERTY, "xyz");
         JsonLdProfileRegistry instance = getJsonLdProfileRegistry();
-        URL annoUrl = getAnnoProfileUrl();
+        URI annoUrl = getAnnoProfileUrl();
         assertTrue(instance.cacheProfile(annoUrl));
         final String httpProxy = System.getProperty("http.proxyHost");
         final String httpsProxy = System.getProperty("https.proxyHost");
@@ -258,7 +258,7 @@ final void testCacheUpdateDelayNotKeepingLocalProfiles() {
         System.setProperty(JsonLdProfileRegistry.DISABLED_UPDATER_PROPERTY, "xyz");
         JsonLdProfileRegistry instance = getJsonLdProfileRegistry(false);
         profileRegistryHidden.init(config, false);
-        URL annoUrl = getAnnoProfileUrl();
+        URI annoUrl = getAnnoProfileUrl();
         assertTrue(instance.cacheProfile(annoUrl));
         final String httpProxy = System.getProperty("http.proxyHost");
         final String httpsProxy = System.getProperty("https.proxyHost");
@@ -324,7 +324,7 @@ final void testGetJsonLdOptions() {
     @Test
     final void testCacheProfile() {
         JsonLdProfileRegistry profileRegistry = getJsonLdProfileRegistry();
-        URL url = this.getAsProfileUrl();
+        URI url = this.getAsProfileUrl();
         assertFalse(profileRegistry.isCachedProfile(url));
         assertTrue(profileRegistry.cacheProfile(url));
         assertTrue(profileRegistry.isCachedProfile(url));
@@ -336,7 +336,7 @@ final void testCacheProfile() {
     @Test
     final void testGetLastUpdateTime() {
         JsonLdProfileRegistry profileRegistry = getJsonLdProfileRegistry();
-        URL url = this.getAnnoProfileUrl();
+        URI url = this.getAnnoProfileUrl();
         assertTrue(profileRegistry.cacheProfile(url));
         assertNotEquals(-1, profileRegistry.getLastUpdateTime(url));
     }