diff --git a/build/lightdb/core/lightdb.php b/build/lightdb/core/lightdb.php
index eb9f1fe..eeec1c5 100644
--- a/build/lightdb/core/lightdb.php
+++ b/build/lightdb/core/lightdb.php
@@ -122,19 +122,16 @@
 		*
 		*/
 		public function insert($key, $data){
-			$already_line = $this->line;
-
 			/* (1) On vérifie que la clé est unique */
 			if( array_key_exists($key, $this->index) )
-				$already_line = $this->index[$key]['line'];
+				return false;
 
 			$key = (string) $key;
 
 			/* (2) On ajoute les données aux fichier */
 			$json_data = json_encode($data);
-			$this->driver->seek($already_line);
-			if( $already_line == $this->line )
-				$this->line++;
+			$this->driver->seek($this->line);
+			$this->line++;
 			$written = $this->driver->fwrite( $json_data.PHP_EOL );
 
 			// Si erreur d'écriture, on retourne FALSE
@@ -143,7 +140,7 @@
 
 			/* (3) On enregistre l'index */
 			$this->index[$key] = [
-				'line' => $already_line - 1,
+				'line' => $this->line - 1,
 				'hash' => sha1($json_data)
 			];