diff --git a/TopModel.Core/FileModel/ModelFile.cs b/TopModel.Core/FileModel/ModelFile.cs
index 6e36cad1..cc69125a 100644
--- a/TopModel.Core/FileModel/ModelFile.cs
+++ b/TopModel.Core/FileModel/ModelFile.cs
@@ -80,6 +80,7 @@ public class ModelFile
         .ToList();
 
     public IList<IProperty> Properties => Classes.SelectMany(c => c.Properties)
+        .Concat(Classes.SelectMany(c => c.FromMapperProperties))
         .Concat(Endpoints.SelectMany(e => e.Params))
         .Concat(Endpoints.Select(e => e.Returns))
         .Concat(Decorators.SelectMany(e => e.Properties))
diff --git a/TopModel.Core/Loaders/ClassLoader.cs b/TopModel.Core/Loaders/ClassLoader.cs
index 4d3200f0..8d117934 100644
--- a/TopModel.Core/Loaders/ClassLoader.cs
+++ b/TopModel.Core/Loaders/ClassLoader.cs
@@ -98,10 +98,7 @@ public Class Load(Parser parser)
                 case "properties":
                     parser.ConsumeSequence(() =>
                     {
-                        foreach (var property in _propertyLoader.Load(parser))
-                        {
-                            classe.Properties.Add(property);
-                        }
+                        classe.Properties.Add(_propertyLoader.Load(parser));
                     });
                     break;
                 case "unique":
@@ -138,7 +135,7 @@ public Class Load(Parser parser)
                             case "from":
                                 parser.ConsumeSequence(() =>
                                 {
-                                    var mapper = new FromMapper();
+                                    var mapper = new FromMapper { Class = classe };
                                     classe.FromMappers.Add(mapper);
 
                                     parser.ConsumeMapping(prop =>
@@ -196,12 +193,10 @@ public Class Load(Parser parser)
                                                             switch (prop.Value)
                                                             {
                                                                 case "property":
-                                                                    foreach (var p in _propertyLoader.Load(parser))
-                                                                    {
-                                                                        var param = new PropertyMapping { Property = p };
-                                                                        mapper.Params.Add(param);
-                                                                    }
-
+                                                                    var p = _propertyLoader.Load(parser);
+                                                                    var param = new PropertyMapping { Property = p, FromMapper = mapper };
+                                                                    p.PropertyMapping = param;
+                                                                    mapper.Params.Add(param);
                                                                     break;
                                                                 case "target":
                                                                     var targetReference = new Reference(parser.Consume<Scalar>());
diff --git a/TopModel.Core/Loaders/DecoratorLoader.cs b/TopModel.Core/Loaders/DecoratorLoader.cs
index 768ec9fe..6d8a7b7c 100644
--- a/TopModel.Core/Loaders/DecoratorLoader.cs
+++ b/TopModel.Core/Loaders/DecoratorLoader.cs
@@ -38,10 +38,7 @@ public Decorator Load(Parser parser)
                 case "properties":
                     parser.ConsumeSequence(() =>
                     {
-                        foreach (var property in _propertyLoader.Load(parser))
-                        {
-                            decorator.Properties.Add(property);
-                        }
+                        decorator.Properties.Add(_propertyLoader.Load(parser));
                     });
                     break;
                 default:
diff --git a/TopModel.Core/Loaders/EndpointLoader.cs b/TopModel.Core/Loaders/EndpointLoader.cs
index a718e765..f7ab4456 100644
--- a/TopModel.Core/Loaders/EndpointLoader.cs
+++ b/TopModel.Core/Loaders/EndpointLoader.cs
@@ -45,17 +45,14 @@ public Endpoint Load(Parser parser)
                 case "params":
                     parser.ConsumeSequence(() =>
                     {
-                        foreach (var property in _propertyLoader.Load(parser))
-                        {
-                            property.Endpoint = endpoint;
-                            endpoint.Params.Add(property);
-                        }
+                        var property = _propertyLoader.Load(parser);
+                        property.Endpoint = endpoint;
+                        endpoint.Params.Add(property);
                     });
                     break;
                 case "returns":
-                    endpoint.Returns = _propertyLoader.Load(parser).First();
+                    endpoint.Returns = _propertyLoader.Load(parser);
                     endpoint.Returns.Endpoint = endpoint;
-                    parser.Consume<MappingEnd>();
                     break;
                 case "decorators":
                     parser.ConsumeSequence(() =>
diff --git a/TopModel.Core/Loaders/PropertyLoader.cs b/TopModel.Core/Loaders/PropertyLoader.cs
index 4544006a..e653b465 100644
--- a/TopModel.Core/Loaders/PropertyLoader.cs
+++ b/TopModel.Core/Loaders/PropertyLoader.cs
@@ -4,7 +4,7 @@
 
 namespace TopModel.Core.Loaders;
 
-public class PropertyLoader : ILoader<IEnumerable<IProperty>>
+public class PropertyLoader : ILoader<IProperty>
 {
     private readonly ModelConfig _modelConfig;
 
@@ -14,7 +14,7 @@ public PropertyLoader(ModelConfig modelConfig)
     }
 
     /// <inheritdoc cref="ILoader{T}.Load" />
-    public IEnumerable<IProperty> Load(Parser parser)
+    public IProperty Load(Parser parser)
     {
         parser.Consume<MappingStart>();
         switch (parser.Current)
@@ -67,8 +67,8 @@ public IEnumerable<IProperty> Load(Parser parser)
                     rp.Required = true;
                 }
 
-                yield return rp;
-                break;
+                parser.Consume<MappingEnd>();
+                return rp;
 
             case Scalar { Value: "association" } s:
                 var ap = new AssociationProperty
@@ -136,8 +136,8 @@ public IEnumerable<IProperty> Load(Parser parser)
                     ap.Required = true;
                 }
 
-                yield return ap;
-                break;
+                parser.Consume<MappingEnd>();
+                return ap;
 
             case Scalar { Value: "composition" } s:
                 var cp = new CompositionProperty
@@ -172,8 +172,8 @@ public IEnumerable<IProperty> Load(Parser parser)
                     }
                 }
 
-                yield return cp;
-                break;
+                parser.Consume<MappingEnd>();
+                return cp;
 
             case Scalar { Value: "alias" } s:
                 var aliasReference = new AliasReference();
@@ -274,13 +274,11 @@ public IEnumerable<IProperty> Load(Parser parser)
                 }
 
                 alp.Reference = aliasReference;
-                yield return alp;
-                break;
+                parser.Consume<MappingEnd>();
+                return alp;
 
             default:
                 throw new ModelException($"Type de propriété inconnu.");
         }
-
-        parser.Consume<MappingEnd>();
     }
 }
\ No newline at end of file
diff --git a/TopModel.Core/Model/AliasProperty.cs b/TopModel.Core/Model/AliasProperty.cs
index 27fff770..00dc3b19 100644
--- a/TopModel.Core/Model/AliasProperty.cs
+++ b/TopModel.Core/Model/AliasProperty.cs
@@ -39,6 +39,8 @@ public IFieldProperty Property
 
     public Decorator Decorator { get; set; }
 
+    public PropertyMapping PropertyMapping { get; set; }
+
 #nullable enable
 
     public LocatedString? Trigram { get; set; }
diff --git a/TopModel.Core/Model/AssociationProperty.cs b/TopModel.Core/Model/AssociationProperty.cs
index f9ee3990..2b4ede23 100644
--- a/TopModel.Core/Model/AssociationProperty.cs
+++ b/TopModel.Core/Model/AssociationProperty.cs
@@ -31,6 +31,8 @@ public IFieldProperty Property
     public Endpoint Endpoint { get; set; }
 
     public Decorator Decorator { get; set; }
+
+    public PropertyMapping PropertyMapping { get; set; }
 #nullable enable
 
     public string? Role { get; set; }
diff --git a/TopModel.Core/Model/Class.cs b/TopModel.Core/Model/Class.cs
index 480d8091..5fea0807 100644
--- a/TopModel.Core/Model/Class.cs
+++ b/TopModel.Core/Model/Class.cs
@@ -66,6 +66,8 @@ public class Class : IPropertyContainer
 
     public List<FromMapper> FromMappers { get; } = new();
 
+    public IEnumerable<IProperty> FromMapperProperties => FromMappers.SelectMany(fm => fm.PropertyParams.Select(pp => pp.Property));
+
     public List<ClassMappings> ToMappers { get; } = new();
 
     public string PluralName
diff --git a/TopModel.Core/Model/CompositionProperty.cs b/TopModel.Core/Model/CompositionProperty.cs
index d371b4d7..ecf3f27e 100644
--- a/TopModel.Core/Model/CompositionProperty.cs
+++ b/TopModel.Core/Model/CompositionProperty.cs
@@ -32,6 +32,8 @@ public class CompositionProperty : IProperty
 
     public Decorator Decorator { get; set; }
 
+    public PropertyMapping PropertyMapping { get; set; }
+
     public string Label => Name;
 
     public bool PrimaryKey => false;
diff --git a/TopModel.Core/Model/FromMapper.cs b/TopModel.Core/Model/FromMapper.cs
index 69740c77..757fad6c 100644
--- a/TopModel.Core/Model/FromMapper.cs
+++ b/TopModel.Core/Model/FromMapper.cs
@@ -4,7 +4,6 @@ namespace TopModel.Core;
 
 public class FromMapper
 {
-#nullable enable
     public string? Comment { get; set; }
 
     public List<OneOf<ClassMappings, PropertyMapping>> Params { get; } = new();
@@ -14,5 +13,7 @@ public class FromMapper
     public IEnumerable<PropertyMapping> PropertyParams => Params.Where(p => p.IsT1).Select(p => p.AsT1);
 
 #nullable disable
+    public Class Class { get; set; }
+
     internal LocatedString Reference { get; set; }
 }
diff --git a/TopModel.Core/Model/IProperty.cs b/TopModel.Core/Model/IProperty.cs
index a8b08adb..6e32f351 100644
--- a/TopModel.Core/Model/IProperty.cs
+++ b/TopModel.Core/Model/IProperty.cs
@@ -30,6 +30,8 @@ public interface IProperty
 
     Decorator Decorator { get; set; }
 
+    PropertyMapping PropertyMapping { get; set; }
+
     IPropertyContainer Parent => Class ?? (IPropertyContainer)Endpoint ?? Decorator;
 
     IProperty CloneWithClassOrEndpoint(Class? classe = null, Endpoint? endpoint = null);
diff --git a/TopModel.Core/Model/PropertyMapping.cs b/TopModel.Core/Model/PropertyMapping.cs
index c56ea808..48e42b90 100644
--- a/TopModel.Core/Model/PropertyMapping.cs
+++ b/TopModel.Core/Model/PropertyMapping.cs
@@ -10,4 +10,6 @@ public class PropertyMapping
     public IProperty TargetProperty { get; set; }
 
     public Reference TargetPropertyReference { get; set; }
+
+    public FromMapper FromMapper { get; set; }
 }
diff --git a/TopModel.Core/Model/RegularProperty.cs b/TopModel.Core/Model/RegularProperty.cs
index 976289b6..1c352c54 100644
--- a/TopModel.Core/Model/RegularProperty.cs
+++ b/TopModel.Core/Model/RegularProperty.cs
@@ -41,6 +41,8 @@ public class RegularProperty : IFieldProperty
 
     public Decorator Decorator { get; set; }
 
+    public PropertyMapping PropertyMapping { get; set; }
+
     public DomainReference DomainReference { get; set; }
 
 #nullable enable
diff --git a/TopModel.Core/ModelExtensions.cs b/TopModel.Core/ModelExtensions.cs
index 5826c82c..acb96e55 100644
--- a/TopModel.Core/ModelExtensions.cs
+++ b/TopModel.Core/ModelExtensions.cs
@@ -7,6 +7,7 @@ public static class ModelExtensions
     public static IEnumerable<(ClassReference Reference, ModelFile File)> GetClassReferences(this ModelStore modelStore, Class classe)
     {
         return modelStore.Classes.SelectMany(c => c.Properties)
+            .Concat(modelStore.Classes.SelectMany(c => c.FromMapperProperties))
             .Concat(modelStore.Endpoints.SelectMany(e => e.Properties))
             .Concat(modelStore.Decorators.SelectMany(d => d.Properties))
             .Where(p =>
@@ -54,6 +55,7 @@ public static class ModelExtensions
     public static IEnumerable<(DomainReference Reference, ModelFile File)> GetDomainReferences(this ModelStore modelStore, Domain domain)
     {
         return modelStore.Classes.SelectMany(c => c.Properties)
+            .Concat(modelStore.Classes.SelectMany(c => c.FromMapperProperties))
             .Concat(modelStore.Decorators.SelectMany(c => c.Properties))
             .Concat(modelStore.Endpoints.SelectMany(e => e.Properties))
             .Where(p =>
@@ -86,6 +88,7 @@ public static ModelFile GetFile(this object? objet)
             IProperty { Decorator: Decorator decorator } => decorator.ModelFile,
             IProperty { Class: Class classe } => classe.ModelFile,
             IProperty { Endpoint: Endpoint endpoint } => endpoint.ModelFile,
+            IProperty { PropertyMapping: PropertyMapping param } => param.FromMapper.Class.ModelFile,
             Domain domain => domain.ModelFile,
             Converter converter => converter.ModelFile,
             Decorator decorator => decorator.ModelFile,
diff --git a/TopModel.Core/ModelStore.cs b/TopModel.Core/ModelStore.cs
index af147cd1..fec94afb 100644
--- a/TopModel.Core/ModelStore.cs
+++ b/TopModel.Core/ModelStore.cs
@@ -670,13 +670,32 @@ private IEnumerable<ModelError> ResolveReferences(ModelFile modelFile)
                 if (alp.OriginalAliasProperty is not null)
                 {
                     var index = classe.Properties.IndexOf(alp);
-                    classe.Properties.RemoveAt(classe.Properties.IndexOf(alp));
+                    classe.Properties.RemoveAt(index);
                     if (!classe.Properties.Contains(alp.OriginalAliasProperty))
                     {
                         classe.Properties.Insert(index, alp.OriginalAliasProperty);
                     }
                 }
             }
+
+            foreach (var alp in classe.FromMapperProperties.OfType<AliasProperty>().ToList())
+            {
+                if (alp.OriginalAliasProperty is not null)
+                {
+                    var index = alp.PropertyMapping.FromMapper.Params.IndexOf(alp.PropertyMapping);
+                    alp.PropertyMapping.FromMapper.Params.RemoveAt(index);
+                    if (!alp.PropertyMapping.FromMapper.Params.Contains(alp.OriginalAliasProperty.PropertyMapping))
+                    {
+                        alp.PropertyMapping.FromMapper.Params.Insert(index, new PropertyMapping
+                        {
+                            FromMapper = alp.PropertyMapping.FromMapper,
+                            Property = alp.OriginalAliasProperty,
+                            TargetProperty = alp.PropertyMapping.TargetProperty,
+                            TargetPropertyReference = alp.PropertyMapping.TargetPropertyReference
+                        });
+                    }
+                }
+            }
         }
 
         // Reset des alias déjà résolus sur les endpoints.
@@ -803,6 +822,22 @@ IEnumerable<ModelError> ResolveAliases(IEnumerable<AliasProperty> alps)
                             alp.Decorator.Properties.Insert(index + 1, prop);
                         }
                     }
+                    else if (alp.PropertyMapping != null)
+                    {
+                        var index = alp.PropertyMapping.FromMapper.Params.IndexOf(alp.PropertyMapping);
+                        if (index >= 0)
+                        {
+                            var mapping = new PropertyMapping
+                            {
+                                FromMapper = alp.PropertyMapping.FromMapper,
+                                Property = prop,
+                                TargetProperty = alp.PropertyMapping.TargetProperty,
+                                TargetPropertyReference = alp.PropertyMapping.TargetPropertyReference,
+                            };
+                            prop.PropertyMapping = mapping;
+                            alp.PropertyMapping.FromMapper.Params.Insert(index + 1, mapping);
+                        }
+                    }
                 }
 
                 if (alp.Class != null)
@@ -813,6 +848,10 @@ IEnumerable<ModelError> ResolveAliases(IEnumerable<AliasProperty> alps)
                 {
                     alp.Endpoint.Params.Remove(alp);
                 }
+                else if (alp.PropertyMapping != null)
+                {
+                    alp.PropertyMapping.FromMapper.Params.Remove(alp.PropertyMapping);
+                }
                 else
                 {
                     alp.Decorator?.Properties.Remove(alp);