diff --git a/build/api/module/ueController.php b/build/api/module/ueController.php
index a1e891b..e29430a 100644
--- a/build/api/module/ueController.php
+++ b/build/api/module/ueController.php
@@ -64,7 +64,7 @@ class ueController{
 		$volumeTD         = 0;
 		$volumeTP         = 0;
 		$disabled         = true;
-		$defaultFormation = null;
+		$defaultFormation = -1;
 		extract($args);
 
 		/* Get the ue repo */
@@ -87,7 +87,7 @@ class ueController{
 			$volumeTD,
 			$volumeTP,
 			$disabled,
-			$defaultFormation
+			is_int($defaultFormation) && $defaultFormation < 0 ? null : $defaultFormation
 		);
 
 
@@ -145,7 +145,7 @@ class ueController{
 		$volumeTD         = 0;
 		$volumeTP         = 0;
 		$disabled         = true;
-		$defaultFormation = null;
+		$defaultFormation = -1;
 		extract($args);
 
 		/* Get the ue repo */
@@ -161,7 +161,7 @@ class ueController{
 			$volumeTD,
 			$volumeTP,
 			$disabled,
-			$defaultFormation < 0 ? null : $defaultFormation
+			is_int($defaultFormation) && $defaultFormation < 0 ? null : $defaultFormation
 		)];
 
 	}
diff --git a/config/modules.json b/config/modules.json
index cbb732b..4f744ef 100644
--- a/config/modules.json
+++ b/config/modules.json
@@ -185,14 +185,14 @@
 			"des": "Creates a new UE",
 			"per": [],
 			"par": {
-				"code":             { "des": "UE code.",                           "typ": "varchar(4,20,alphanumeric)" },
-				"label":            { "des": "UE label",                           "typ": "varchar(4,30,alphanumeric)" },
-				"required":         { "des": "If UE is required",                  "typ": "bool"                       },
-				"volumeCours":      { "des": "Number of course hours for UE",      "typ": "float"                      },
-				"volumeTD":         { "des": "Number of TD hours for UE",          "typ": "float"                      },
-				"volumeTP":         { "des": "Number of TP hours for UE",          "typ": "float"                      },
-				"disabled":         { "des": "Whether UE is disabled",             "typ": "boolean"                    },
-				"defaultFormation": { "des": "UID for optional default formation", "typ": "id", "opt": true            }
+				"code":             { "des": "UE code.",                                        "typ": "varchar(4,20,alphanumeric)"  },
+				"label":            { "des": "UE label",                                        "typ": "varchar(4,30,alphanumeric)"  },
+				"required":         { "des": "If UE is required",                               "typ": "bool"                        },
+				"volumeCours":      { "des": "Number of course hours for UE",                   "typ": "float"                       },
+				"volumeTD":         { "des": "Number of TD hours for UE",                       "typ": "float"                       },
+				"volumeTP":         { "des": "Number of TP hours for UE",                       "typ": "float"                       },
+				"disabled":         { "des": "Whether UE is disabled",                          "typ": "boolean"                     },
+				"defaultFormation": { "des": "UID for optional default formation (-1 if none)", "typ": "int", "opt": true, "def": -1 }
 			},
 			"out": {
 				"created_code": { "des": "Created UE code", "typ": "varchar(4,20,alphanumeric)" }