diff --git a/ChangeLog b/ChangeLog
index f30dfc259..44e1d9990 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -66,6 +66,7 @@
   Sulfrian).
 - Added certificate hostname verification (thanks to Alexander Sulfrian).
 - Removed debugging code.
+- Added details in debug mode, for unrecognized data (thanks to Kosta H).
 
 ------ current release ---------------------------
 
diff --git a/src/Task.cpp b/src/Task.cpp
index 21e90395a..faed352b7 100644
--- a/src/Task.cpp
+++ b/src/Task.cpp
@@ -854,6 +854,11 @@ void Task::parseLegacy (const std::string& line)
     break;
 
   default:
+    std::stringstream message;
+    message << "Invalid fileformat at line '"
+            << line
+            << "'";
+    context.debug (message.str());
     throw std::string (STRING_TASK_PARSE_UNREC_FF);
     break;
   }