diff --git a/src/main/java/de/malkusch/km200/KM200.java b/src/main/java/de/malkusch/km200/KM200.java
index da9df32..06cd064 100644
--- a/src/main/java/de/malkusch/km200/KM200.java
+++ b/src/main/java/de/malkusch/km200/KM200.java
@@ -267,8 +267,12 @@ private static void assertHttpUri(String var) {
         assertNotBlank(var, "Wrong uri " + var);
         var uri = URI.create(var);
 
-        var scheme = uri.getScheme();
-        if (scheme == null || !(scheme.equalsIgnoreCase("http") || scheme.equalsIgnoreCase("https"))) {
+        switch (uri.getScheme()) {
+        case String s when s.equalsIgnoreCase("http"):
+            break;
+        case String s when s.equalsIgnoreCase("https"):
+            break;
+        case null, default:
             throw new IllegalArgumentException("Wrong uri " + var);
         }
     }
diff --git a/src/main/java/de/malkusch/km200/KM200Endpoint.java b/src/main/java/de/malkusch/km200/KM200Endpoint.java
index 9d13945..0a9dc81 100644
--- a/src/main/java/de/malkusch/km200/KM200Endpoint.java
+++ b/src/main/java/de/malkusch/km200/KM200Endpoint.java
@@ -12,7 +12,7 @@
 
 import de.malkusch.km200.KM200Exception.Forbidden;
 
-public abstract class KM200Endpoint {
+public abstract sealed class KM200Endpoint {
     private final String path;
     private final String type;
 
@@ -30,7 +30,7 @@ public String toString() {
         return String.format("%s [%s]", path, type);
     }
 
-    public static class Value extends KM200Endpoint {
+    public static final class Value extends KM200Endpoint {
         private final String body;
         private final boolean writeable;
         private final boolean recordable;
@@ -57,13 +57,13 @@ public String toString() {
         }
     }
 
-    public static class ForbiddenNode extends KM200Endpoint {
+    public static final class ForbiddenNode extends KM200Endpoint {
         ForbiddenNode(String path) {
             super(path, "Forbidden");
         }
     }
 
-    public static class UnknownNode extends KM200Endpoint {
+    public static final class UnknownNode extends KM200Endpoint {
         private final String value;
 
         UnknownNode(String path, String type, String value) {
@@ -139,14 +139,11 @@ private static Value value(String path, String type, JsonNode json) {
             var writeable = json.path("writeable").asBoolean(false);
             var recordable = json.path("recordable").asBoolean(false);
 
-            String value;
-            if (json.has("value")) {
-                value = json.get("value").asText();
-            } else if (json.has("values")) {
-                value = json.get("values").toString();
-            } else {
-                value = json.toString();
-            }
+            String value = switch (json) {
+            case JsonNode j when j.has("value") -> json.get("value").asText();
+            case JsonNode j when j.has("values") -> json.get("values").toString();
+            default -> json.toString();
+            };
 
             String allowedValues = null;
             if (json.has("allowedValues")) {
diff --git a/src/main/java/de/malkusch/km200/http/RetryHttp.java b/src/main/java/de/malkusch/km200/http/RetryHttp.java
index 9c0a042..56c36f2 100644
--- a/src/main/java/de/malkusch/km200/http/RetryHttp.java
+++ b/src/main/java/de/malkusch/km200/http/RetryHttp.java
@@ -34,17 +34,11 @@ public Response exchange(Request request) throws IOException, InterruptedExcepti
             return retry.get(() -> http.exchange(request));
 
         } catch (FailsafeException e) {
-            if (e.getCause() instanceof IOException cause) {
-                throw cause;
-
-            } else if (e.getCause() instanceof InterruptedException cause) {
-                throw cause;
-
-            } else if (e.getCause() instanceof KM200Exception cause) {
-                throw cause;
-
-            } else {
-                throw new KM200Exception("Unexpected retry error for " + request.path(), e);
+            switch (e.getCause()) {
+            case IOException cause -> throw cause;
+            case InterruptedException cause -> throw cause;
+            case KM200Exception cause -> throw cause;
+            default -> throw new KM200Exception("Unexpected retry error for " + request.path(), e);
             }
         }
     }
diff --git a/src/main/java/de/malkusch/km200/http/UrlHttp.java b/src/main/java/de/malkusch/km200/http/UrlHttp.java
index becd95c..65654d9 100644
--- a/src/main/java/de/malkusch/km200/http/UrlHttp.java
+++ b/src/main/java/de/malkusch/km200/http/UrlHttp.java
@@ -63,7 +63,12 @@ protected Response exchange(Request request) throws IOException, InterruptedExce
 
     private HttpURLConnection connect(Request request) throws IOException {
         try {
-            var connection = (HttpURLConnection) new URL(uri + request.path()).openConnection();
+            var url = new URL(uri + request.path());
+
+            if (!(url.openConnection() instanceof HttpURLConnection connection)) {
+                throw new IllegalStateException(url + " is not a http url");
+            }
+
             connection.setConnectTimeout(timeoutMillis);
             connection.setReadTimeout(timeoutMillis);
             connection.setRequestProperty("User-Agent", userAgent);
@@ -74,7 +79,6 @@ private HttpURLConnection connect(Request request) throws IOException {
             }
 
             connection.connect();
-
             return connection;
 
         } catch (MalformedURLException e) {