diff --git a/moulinette/interfaces/api.py b/moulinette/interfaces/api.py
index 34b51143..bf3b0c7f 100644
--- a/moulinette/interfaces/api.py
+++ b/moulinette/interfaces/api.py
@@ -353,11 +353,18 @@ class _ActionsMapPlugin:
 
         """
 
-        if "credentials" not in request.params:
-            raise HTTPResponse("Missing credentials parameter", 400)
-        credentials = request.params["credentials"]
+        if request.get_header("Content-Type") == "application/json":
+            if "credentials" not in request.json:
+                raise HTTPResponse("Missing credentials parameter", 400)
+            credentials = request.json["credentials"]
+            profile = request.json.get("profile", self.actionsmap.default_authentication)
+        else:
+            if "credentials" not in request.params:
+                raise HTTPResponse("Missing credentials parameter", 400)
+            credentials = request.params["credentials"]
+
+            profile = request.params.get("profile", self.actionsmap.default_authentication)
 
-        profile = request.params.get("profile", self.actionsmap.default_authentication)
         authenticator = self.actionsmap.get_authenticator(profile)
 
         try:
@@ -732,7 +739,7 @@ class Interface:
             def wrapper(*args, **kwargs):
                 try:
                     locale = request.params.pop("locale")
-                except KeyError:
+                except (KeyError, ValueError):
                     locale = m18n.default_locale
                 m18n.set_locale(locale)
                 return callback(*args, **kwargs)