diff --git a/TLS-Core/src/main/java/de/rub/nds/tlsattacker/core/protocol/message/AlertMessage.java b/TLS-Core/src/main/java/de/rub/nds/tlsattacker/core/protocol/message/AlertMessage.java
index acc92e3742..2a347d20ee 100644
--- a/TLS-Core/src/main/java/de/rub/nds/tlsattacker/core/protocol/message/AlertMessage.java
+++ b/TLS-Core/src/main/java/de/rub/nds/tlsattacker/core/protocol/message/AlertMessage.java
@@ -114,11 +114,23 @@ public String toCompactString() {
         StringBuilder sb = new StringBuilder();
         String levelString;
         String descriptionString;
+
+        // Determine level string
         if (level != null && level.getValue() != null) {
             levelString = AlertLevel.getAlertLevel(level.getValue()).name();
+        } else if (config != null && config.length == 2) {
+            // Use config as fallback for level
+            AlertLevel alertLevel = AlertLevel.getAlertLevel((byte) config[0]);
+            if (alertLevel != null) {
+                levelString = alertLevel.name();
+            } else {
+                levelString = "" + config[0];
+            }
         } else {
-            levelString = "null";
+            levelString = "not configured";
         }
+
+        // Determine description string
         if (description != null && description.getValue() != null) {
             AlertDescription desc = AlertDescription.getAlertDescription(description.getValue());
             if (desc != null) {
@@ -126,18 +138,18 @@ public String toCompactString() {
             } else {
                 descriptionString = "" + description.getValue();
             }
-        } else {
-            if (config != null && config.length == 2) {
-                AlertDescription desc = AlertDescription.getAlertDescription((byte) config[1]);
-                if (desc != null) {
-                    descriptionString = desc.name();
-                } else {
-                    descriptionString = "" + config[1];
-                }
+        } else if (config != null && config.length == 2) {
+            // Use config as fallback for description
+            AlertDescription desc = AlertDescription.getAlertDescription((byte) config[1]);
+            if (desc != null) {
+                descriptionString = desc.name();
             } else {
-                descriptionString = "null";
+                descriptionString = "" + config[1];
             }
+        } else {
+            descriptionString = "not configured";
         }
+
         sb.append("Alert(").append(levelString).append(",").append(descriptionString).append(")");
         return sb.toString();
     }
diff --git a/TLS-Core/src/test/java/de/rub/nds/tlsattacker/core/protocol/message/AlertMessageToCompactStringTest.java b/TLS-Core/src/test/java/de/rub/nds/tlsattacker/core/protocol/message/AlertMessageToCompactStringTest.java
new file mode 100644
index 0000000000..c41a01797d
--- /dev/null
+++ b/TLS-Core/src/test/java/de/rub/nds/tlsattacker/core/protocol/message/AlertMessageToCompactStringTest.java
@@ -0,0 +1,84 @@
+/*
+ * TLS-Attacker - A Modular Penetration Testing Framework for TLS
+ *
+ * Copyright 2014-2023 Ruhr University Bochum, Paderborn University, Technology Innovation Institute, and Hackmanit GmbH
+ *
+ * Licensed under Apache License, Version 2.0
+ * http://www.apache.org/licenses/LICENSE-2.0.txt
+ */
+package de.rub.nds.tlsattacker.core.protocol.message;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import de.rub.nds.tlsattacker.core.constants.AlertDescription;
+import de.rub.nds.tlsattacker.core.constants.AlertLevel;
+import org.junit.jupiter.api.Test;
+
+public class AlertMessageToCompactStringTest {
+
+    @Test
+    public void testToCompactStringWithNullValues() {
+        AlertMessage message = new AlertMessage();
+        // Both level and description are null, no config set
+        assertEquals("Alert(not configured,not configured)", message.toCompactString());
+    }
+
+    @Test
+    public void testToCompactStringWithConfig() {
+        AlertMessage message = new AlertMessage();
+        // Set config with WARNING level (1) and BAD_RECORD_MAC description (20)
+        message.setConfig(new byte[] {1, 20});
+        assertEquals("Alert(WARNING,BAD_RECORD_MAC)", message.toCompactString());
+    }
+
+    @Test
+    public void testToCompactStringWithExplicitValues() {
+        AlertMessage message = new AlertMessage();
+        message.setLevel(AlertLevel.FATAL.getValue());
+        message.setDescription(AlertDescription.HANDSHAKE_FAILURE.getValue());
+        assertEquals("Alert(FATAL,HANDSHAKE_FAILURE)", message.toCompactString());
+    }
+
+    @Test
+    public void testToCompactStringWithUnknownValues() {
+        AlertMessage message = new AlertMessage();
+        // Use values that don't correspond to known alert types
+        message.setConfig(new byte[] {99, 99});
+        assertEquals("Alert(UNDEFINED,99)", message.toCompactString());
+    }
+
+    @Test
+    public void testToCompactStringWithPartialConfig() {
+        AlertMessage message = new AlertMessage();
+        // Config with only one byte - should fall back to "not configured"
+        message.setConfig(new byte[] {1});
+        assertEquals("Alert(not configured,not configured)", message.toCompactString());
+    }
+
+    @Test
+    public void testToCompactStringWithLevelButNoDescription() {
+        AlertMessage message = new AlertMessage();
+        message.setLevel(AlertLevel.WARNING.getValue());
+        // Description is null, no config
+        assertEquals("Alert(WARNING,not configured)", message.toCompactString());
+    }
+
+    @Test
+    public void testToCompactStringWithDescriptionButNoLevel() {
+        AlertMessage message = new AlertMessage();
+        message.setDescription(AlertDescription.CLOSE_NOTIFY.getValue());
+        // Level is null, no config
+        assertEquals("Alert(not configured,CLOSE_NOTIFY)", message.toCompactString());
+    }
+
+    @Test
+    public void testToCompactStringPrefersExplicitValuesOverConfig() {
+        AlertMessage message = new AlertMessage();
+        // Set config
+        message.setConfig(new byte[] {1, 20});
+        // But also set explicit values - these should take precedence
+        message.setLevel(AlertLevel.FATAL.getValue());
+        message.setDescription(AlertDescription.UNEXPECTED_MESSAGE.getValue());
+        assertEquals("Alert(FATAL,UNEXPECTED_MESSAGE)", message.toCompactString());
+    }
+}