1 files changed, 2 insertions, 2 deletions
diff --git a/src/main/java/org/traccar/model/ExtendedModel.java b/src/main/java/org/traccar/model/ExtendedModel.java
index 9da9c7529..0a0923ba1 100644
--- a/src/main/java/org/traccar/model/ExtendedModel.java
+++ b/src/main/java/org/traccar/model/ExtendedModel.java
@@ -91,8 +91,8 @@ public class ExtendedModel extends BaseModel {
 
     public String getString(String key, String defaultValue) {
         if (attributes.containsKey(key)) {
-            Object value = attributes.get(key);
-            return value != null ? value.toString() : value;
+            Object value = attributes.containsKey(key);
+            return value != null ? value.toString() : null;
         } else {
             return defaultValue;
         }