diff --git a/src/uws/service/file/DefaultOwnerGroupIdentifier.java b/src/uws/service/file/DefaultOwnerGroupIdentifier.java
index a55645e1fed60b8098baa99c8cc26e0b8a8eef01..3087e0320acbc90c85fa649c0fe302f43f03ec77 100644
--- a/src/uws/service/file/DefaultOwnerGroupIdentifier.java
+++ b/src/uws/service/file/DefaultOwnerGroupIdentifier.java
@@ -44,7 +44,7 @@ public class DefaultOwnerGroupIdentifier implements OwnerGroupIdentifier {
 			return null;
 		else{
 			// The user directory name = userID in which each directory separator char are replaced by a _ (=> no confusion with a path):
-			String userDir = owner.getID().trim().replaceAll(File.separator, "_");
+			String userDir = owner.getID().trim().replaceAll(Pattern.quote(File.separator), "_");
 
 			// The parent directory = the first LETTER of the userID or _ if none can be found:
 			String parentDir = "_";
diff --git a/src/uws/service/file/LocalUWSFileManager.java b/src/uws/service/file/LocalUWSFileManager.java
index 05848c10889dcf75ddd52b92f57fcda6df3740a8..0ca787e746bf8eb0300e0eeaab77a5975ead25cc 100644
--- a/src/uws/service/file/LocalUWSFileManager.java
+++ b/src/uws/service/file/LocalUWSFileManager.java
@@ -40,6 +40,7 @@ import java.util.Date;
 import java.util.Iterator;
 import java.util.List;
 import java.util.NoSuchElementException;
+import java.util.regex.Pattern;
 
 import uws.UWSException;
 import uws.UWSToolBox;
@@ -214,7 +215,7 @@ public class LocalUWSFileManager implements UWSFileManager {
 			if (ownerGroup != null)
 				ownerDir = new File(rootDirectory, ownerGroup);
 		}
-		ownerDir = new File(ownerDir, owner.getID().replaceAll(File.separator, "_"));
+		ownerDir = new File(ownerDir, owner.getID().replaceAll(Pattern.quote(File.separator), "_"));
 
 		return ownerDir;
 	}
@@ -713,7 +714,7 @@ public class LocalUWSFileManager implements UWSFileManager {
 	protected String getBackupFileName(final JobOwner owner) throws IllegalArgumentException{
 		if (owner == null || owner.getID() == null || owner.getID().trim().isEmpty())
 			throw new IllegalArgumentException("Missing owner! Can not get the backup file of an unknown owner.");
-		return owner.getID().replaceAll(File.separator, "_") + ".backup";
+		return owner.getID().replaceAll(Pattern.quote(File.separator), "_") + ".backup";
 	}
 
 	@Override