diff --git a/src/fr/devinsy/sikevadb/SQLSikevaDB.java b/src/fr/devinsy/sikevadb/SQLSikevaDB.java
index bf8dbb0..8180b64 100644
--- a/src/fr/devinsy/sikevadb/SQLSikevaDB.java
+++ b/src/fr/devinsy/sikevadb/SQLSikevaDB.java
@@ -108,7 +108,8 @@ public class SQLSikevaDB implements SikevaDB {
 				//
 				connection = getConnection();
 				connection.setAutoCommit(true);
-				statement = connection.prepareStatement("UPDATE sikevadb_elements SET ARCHIVE_DATE=? WHERE TOPKEY=? AND SUBKEY IS NULL");
+				statement = connection
+						.prepareStatement("UPDATE sikevadb_elements SET ARCHIVE_DATE=? WHERE TOPKEY=? AND SUBKEY IS NULL AND ARCHIVE_DATE IS NULL");
 
 				statement.setTimestamp(1, toTimestamp(element.getArchiveDate()));
 				statement.setString(2, element.getKey());
@@ -147,7 +148,7 @@ public class SQLSikevaDB implements SikevaDB {
 					//
 					connection = getConnection();
 					connection.setAutoCommit(true);
-					statement = connection.prepareStatement("UPDATE sikevadb_elements SET ARCHIVE_DATE=? WHERE TOPKEY=? AND SUBKEY=?");
+					statement = connection.prepareStatement("UPDATE sikevadb_elements SET ARCHIVE_DATE=? WHERE TOPKEY=? AND SUBKEY=? AND ARCHIVE_DATE IS NULL");
 
 					statement.setTimestamp(1, toTimestamp(element.getArchiveDate()));
 					statement.setString(2, element.getKey());
@@ -1715,7 +1716,7 @@ public class SQLSikevaDB implements SikevaDB {
 				connection.setAutoCommit(false);
 
 				// Archive existing element.
-				statement = connection.prepareStatement("UPDATE sikevadb_elements SET ARCHIVE_DATE=? WHERE TOPKEY=? AND SUBKEY IS NULL");
+				statement = connection.prepareStatement("UPDATE sikevadb_elements SET ARCHIVE_DATE=? WHERE TOPKEY=? AND SUBKEY IS NULL AND ARCHIVE_DATE IS NULL");
 
 				statement.setTimestamp(1, toTimestamp(element.getEditionDate()));
 				statement.setString(2, element.getKey());
@@ -1784,7 +1785,7 @@ public class SQLSikevaDB implements SikevaDB {
 				connection.setAutoCommit(false);
 
 				// Archive existing element.
-				statement = connection.prepareStatement("UPDATE sikevadb_elements SET ARCHIVE_DATE=? WHERE TOPKEY=? AND SUBKEY=?");
+				statement = connection.prepareStatement("UPDATE sikevadb_elements SET ARCHIVE_DATE=? WHERE TOPKEY=? AND SUBKEY=? AND ARCHIVE_DATE IS NULL");
 
 				statement.setTimestamp(1, toTimestamp(element.getEditionDate()));
 				statement.setString(2, element.getKey());