diff --git a/common/source/java/ch/systemsx/cisd/common/filesystem/RemoteDirectoryCopyActivitySensor.java b/common/source/java/ch/systemsx/cisd/common/filesystem/RemoteDirectoryCopyActivitySensor.java
index f42dd1c5e43ba2b9738b880d682abe5d7727281a..d8e9fe0f4e938fbd84d3f32cd1771d42fee85bac 100644
--- a/common/source/java/ch/systemsx/cisd/common/filesystem/RemoteDirectoryCopyActivitySensor.java
+++ b/common/source/java/ch/systemsx/cisd/common/filesystem/RemoteDirectoryCopyActivitySensor.java
@@ -61,7 +61,8 @@ public final class RemoteDirectoryCopyActivitySensor extends AbstractCopyActivit
             return StatusWithResult.create(lastChanged);
         } catch (UnknownLastChangedException ex)
         {
-            return StatusWithResult.<Long> createError("Cannot determine time of last change of "
+            return StatusWithResult
+                    .<Long> createRetriableError("Cannot determine time of last change of "
                     + getTargetDescription());
         }
     }