diff --git a/src/main/java/de/malkusch/km200/http/UrlHttp.java b/src/main/java/de/malkusch/km200/http/UrlHttp.java
index d6fc9b8..d6a0ff2 100644
--- a/src/main/java/de/malkusch/km200/http/UrlHttp.java
+++ b/src/main/java/de/malkusch/km200/http/UrlHttp.java
@@ -4,6 +4,7 @@
 import java.net.HttpURLConnection;
 import java.net.SocketTimeoutException;
 import java.net.URL;
+import java.net.http.HttpClient;
 import java.net.http.HttpTimeoutException;
 import java.time.Duration;
 
@@ -16,6 +17,15 @@ public final class UrlHttp extends Http {
     private final String userAgent;
     private final int timeoutMillis;
 
+    /**
+     * Avoid undesired POST retries from UrlConnection
+     * 
+     * {@link HttpClient}
+     */
+    static {
+        System.setProperty("sun.net.http.retryPost", "false");
+    }
+
     public UrlHttp(String uri, String userAgent, Duration timeout) {
         this.uri = uri;
         this.userAgent = userAgent;
diff --git a/src/test/java/de/malkusch/km200/KM200Test.java b/src/test/java/de/malkusch/km200/KM200Test.java
index 3ae04ed..f2568e7 100644
--- a/src/test/java/de/malkusch/km200/KM200Test.java
+++ b/src/test/java/de/malkusch/km200/KM200Test.java
@@ -5,7 +5,6 @@
 import static com.github.tomakehurst.wiremock.client.WireMock.equalTo;
 import static com.github.tomakehurst.wiremock.client.WireMock.get;
 import static com.github.tomakehurst.wiremock.client.WireMock.getRequestedFor;
-import static com.github.tomakehurst.wiremock.client.WireMock.lessThanOrExactly;
 import static com.github.tomakehurst.wiremock.client.WireMock.notFound;
 import static com.github.tomakehurst.wiremock.client.WireMock.ok;
 import static com.github.tomakehurst.wiremock.client.WireMock.post;
@@ -404,7 +403,6 @@ public void updateShouldNotRetryOnBadResponse(Fault fault) throws Exception {
         var km200 = new KM200(URI, TIMEOUT, GATEWAY_PASSWORD, PRIVATE_PASSWORD, SALT);
 
         assertThrows(IOException.class, () -> km200.update("/update-bad-response-retry", 42));
-        // verify(lessThanOrExactly(2), postRequestedFor(urlEqualTo("/update-bad-response-retry")));
         verify(1, postRequestedFor(urlEqualTo("/update-bad-response-retry")));
     }