diff --git a/build/database/repo/ue.php b/build/database/repo/ue.php
index 49d04d4..d9e6e0e 100644
--- a/build/database/repo/ue.php
+++ b/build/database/repo/ue.php
@@ -69,7 +69,7 @@ class ue extends Repo_i {
 	* @volumeTD<float>					[OPT] The UE's new volume of TD
 	* @volumeTP<float>					[OPT] The UE's new volume of TP
 	* @disabled<bool>					[OPT] Whether the UE is disabled
-	* @defaultFormation<int>			[OPT] The default formation foreign key
+	* @defaultFormation<int>			[OPT] The default formation foreign key (-1 to unset)
 	*
 	* @return updated<bool>				Whether the update have been successful
 	*
@@ -86,10 +86,20 @@ class ue extends Repo_i {
 		if( !is_null($volumeTD)         ){ $build_rq[] = '`volumeTD`              = :volumeTD';         $bind_param[':volumeTD']         = $volumeTD;         }
 		if( !is_null($volumeTP)         ){ $build_rq[] = '`volumeTP`              = :volumeTP';         $bind_param[':volumeTP']         = $volumeTP;         }
 		if( !is_null($disabled)         ){ $build_rq[] = '`disabled`              = :disabled';         $bind_param[':disabled']         = $disabled?1:0;     }
-		if( !is_null($defaultFormation) ){ $build_rq[] = '`Formation_idFormation` = :defaultFormation'; $bind_param[':defaultFormation'] = $defaultFormation; }
+
+		// not null @defaultFormation -> set it
+		if( !is_null($defaultFormation) ){
+
+			// if @defaultFormation is (-1) -> unset
+			if( $defaultFormation < 0 ){ $build_rq[] = '`Formation_idFormation` = NULL';                                                                    }
+			// else -> set to new value
+			else{                        $build_rq[] = '`Formation_idFormation` = :defaultFormation'; $bind_param[':defaultFormation'] = $defaultFormation; }
+
+		}
+
 
 		/* (2) ERROR if no updated field */
-		if( count($build_rq) <= 0 || count($bind_param) <= 1 )
+		if( count($build_rq) <= 0 )
 			return FALSE;
 
 		/* (3) Build request */