diff --git a/lib/src/main/java/org/asamk/signal/manager/api/BadRequestException.java b/lib/src/main/java/org/asamk/signal/manager/api/BadRequestException.java
new file mode 100644
index 00000000..bffd9f11
--- /dev/null
+++ b/lib/src/main/java/org/asamk/signal/manager/api/BadRequestException.java
@@ -0,0 +1,19 @@
+package org.asamk.signal.manager.api;
+
+import org.signal.libsignal.net.BadRequestError;
+
+import java.io.IOException;
+
+public class BadRequestException extends IOException {
+
+    private final BadRequestError error;
+
+    public BadRequestException(final BadRequestError error) {
+        super(error.toString());
+        this.error = error;
+    }
+
+    public BadRequestError getError() {
+        return error;
+    }
+}
diff --git a/lib/src/main/java/org/asamk/signal/manager/util/Utils.java b/lib/src/main/java/org/asamk/signal/manager/util/Utils.java
index 27ba298b..674b0ab1 100644
--- a/lib/src/main/java/org/asamk/signal/manager/util/Utils.java
+++ b/lib/src/main/java/org/asamk/signal/manager/util/Utils.java
@@ -1,5 +1,6 @@
 package org.asamk.signal.manager.util;
 
+import org.asamk.signal.manager.api.BadRequestException;
 import org.asamk.signal.manager.api.Pair;
 import org.signal.core.models.ServiceId;
 import org.signal.libsignal.net.BadRequestError;
@@ -194,8 +195,8 @@ public class Utils {
             }
         } else if (result instanceof RequestResult.RetryableNetworkError e) {
             throw e.getNetworkError();
-        } else if (result instanceof RequestResult.NonSuccess) {
-            throw new AssertionError();
+        } else if (result instanceof RequestResult.NonSuccess<?> e) {
+            throw new BadRequestException(e.getError());
         }
         throw new IllegalStateException("Unexpected value: " + result);
     }