diff --git a/schemas/articles/articles.py b/schemas/articles/articles.py
index 0411ac8..2cbcf78 100644
--- a/schemas/articles/articles.py
+++ b/schemas/articles/articles.py
@@ -10,6 +10,7 @@ from utils import (
     normalize_string_field,
 )
 
+
 class Article(BaseModel):
     """Article complet avec tous les enrichissements disponibles"""
 
@@ -355,7 +356,20 @@ class Article(BaseModel):
     )
     exclure: Optional[bool] = Field(None, description="Exclure de certains traitements")
 
-    # ===== VALIDATEURS =====
+    @field_validator("fournisseur_principal", mode="before")
+    @classmethod
+    def convert_fournisseur_principal(cls, v):
+        if v in (None, "", " ", "  "):
+            return None
+        if isinstance(v, str):
+            v = v.strip()
+            if not v:
+                return None
+            try:
+                return int(v)
+            except (ValueError, TypeError):
+                return None
+        return v
 
     @field_validator(
         "unite_vente",