diff --git a/SDAVAssetExportSession.h b/SDAVAssetExportSession.h
index 43def29..f1eae87 100644
--- a/SDAVAssetExportSession.h
+++ b/SDAVAssetExportSession.h
@@ -140,7 +140,7 @@
  *
  * For possible values, see “AVAssetExportSessionStatus.”
  *
- * You can observe this property using key-value observing. (TODO)
+ * You can observe this property using key-value observing.
  */
 @property (nonatomic, assign, readonly) AVAssetExportSessionStatus status;
 
diff --git a/SDAVAssetExportSession.m b/SDAVAssetExportSession.m
index de9164e..a209a36 100755
--- a/SDAVAssetExportSession.m
+++ b/SDAVAssetExportSession.m
@@ -445,4 +445,9 @@ - (void)reset
     self.completionHandler = nil;
 }
 
++ (NSSet *)keyPathsForValuesAffectingStatus
+{
+    return [NSSet setWithObject:@"writer.status"];
+}
+
 @end