diff --git a/src/Discord.Net/API/Image.cs b/src/Discord.Net/API/Image.cs
new file mode 100644
index 000000000..b2357a0a6
--- /dev/null
+++ b/src/Discord.Net/API/Image.cs
@@ -0,0 +1,21 @@
+using System.IO;
+
+namespace Discord.API
+{
+    internal struct Image
+    {
+        public Stream Stream { get; }
+        public string Hash { get; }
+
+        public Image(Stream stream)
+        {
+            Stream = stream;
+            Hash = null;
+        }
+        public Image(string hash)
+        {
+            Stream = null;
+            Hash = hash;
+        }
+    }
+}
diff --git a/src/Discord.Net/API/ImageAttribute.cs b/src/Discord.Net/API/ImageAttribute.cs
deleted file mode 100644
index c31c6d982..000000000
--- a/src/Discord.Net/API/ImageAttribute.cs
+++ /dev/null
@@ -1,7 +0,0 @@
-using System;
-
-namespace Discord.API
-{
-    [AttributeUsage(AttributeTargets.Property)]
-    public class ImageAttribute : Attribute { }
-}
diff --git a/src/Discord.Net/API/Rest/CreateGuildParams.cs b/src/Discord.Net/API/Rest/CreateGuildParams.cs
index 09c294b5e..75892a0e2 100644
--- a/src/Discord.Net/API/Rest/CreateGuildParams.cs
+++ b/src/Discord.Net/API/Rest/CreateGuildParams.cs
@@ -10,7 +10,13 @@ namespace Discord.API.Rest
         [JsonProperty("region")]
         public string Region { get; set; }
 
-        [JsonProperty("icon"), Image]
-        public Optional<Stream> Icon { get; set; }
+        [JsonProperty("icon")]
+        private Optional<Image> _icon { get; set; }
+        [JsonIgnore]
+        public Optional<Stream> Icon
+        {
+            get { return _icon.IsSpecified ? _icon.Value.Stream : null; }
+            set { _icon = value.IsSpecified ? new Image(value.Value) : Optional.Create<Image>(); }
+        }
     }
 }
diff --git a/src/Discord.Net/API/Rest/ModifyCurrentUserParams.cs b/src/Discord.Net/API/Rest/ModifyCurrentUserParams.cs
index 7e9b668ef..03fe3550c 100644
--- a/src/Discord.Net/API/Rest/ModifyCurrentUserParams.cs
+++ b/src/Discord.Net/API/Rest/ModifyCurrentUserParams.cs
@@ -7,7 +7,20 @@ namespace Discord.API.Rest
     {
         [JsonProperty("username")]
         public Optional<string> Username { get; set; }
-        [JsonProperty("avatar"), Image]
-        public Optional<Stream> Avatar { get; set; }
+
+        [JsonProperty("avatar")]
+        private Optional<Image> _avatar { get; set; }
+        [JsonIgnore]
+        public Optional<Stream> Avatar
+        {
+            get { return _avatar.IsSpecified ? _avatar.Value.Stream : null; }
+            set { _avatar = value.IsSpecified ? new Image(value.Value) : Optional.Create<Image>(); }
+        }
+        [JsonIgnore]
+        internal Optional<string> AvatarHash
+        {
+            get { return _avatar.IsSpecified ? _avatar.Value.Hash : null; }
+            set { _avatar = value.IsSpecified ? new Image(value.Value) : Optional.Create<Image>(); }
+        }
     }
 }
diff --git a/src/Discord.Net/API/Rest/ModifyGuildParams.cs b/src/Discord.Net/API/Rest/ModifyGuildParams.cs
index bbdd46d28..f111ceaea 100644
--- a/src/Discord.Net/API/Rest/ModifyGuildParams.cs
+++ b/src/Discord.Net/API/Rest/ModifyGuildParams.cs
@@ -4,7 +4,10 @@ using System.IO;
 namespace Discord.API.Rest
 {
     public class ModifyGuildParams
-    {        
+    {
+        [JsonProperty("username")]
+        public Optional<string> Username { get; set; }
+
         [JsonProperty("name")]
         public Optional<string> Name { get; set; }
         [JsonProperty("region")]
@@ -15,10 +18,36 @@ namespace Discord.API.Rest
         public Optional<DefaultMessageNotifications> DefaultMessageNotifications { get; set; }
         [JsonProperty("afk_timeout")]
         public Optional<int> AFKTimeout { get; set; }
-        [JsonProperty("icon"), Image]
-        public Optional<Stream> Icon { get; set; }
-        [JsonProperty("splash"), Image]
-        public Optional<Stream> Splash { get; set; }
+
+        [JsonProperty("icon")]
+        private Optional<Image> _icon { get; set; }
+        [JsonIgnore]
+        public Optional<Stream> Icon
+        {
+            get { return _icon.IsSpecified ? _icon.Value.Stream : null; }
+            set { _icon = value.IsSpecified ? new Image(value.Value) : Optional.Create<Image>(); }
+        }
+        [JsonIgnore]
+        internal Optional<string> IconHash
+        {
+            get { return _icon.IsSpecified ? _icon.Value.Hash : null; }
+            set { _icon = value.IsSpecified ? new Image(value.Value) : Optional.Create<Image>(); }
+        }
+
+        [JsonProperty("splash")]
+        private Optional<Image> _splash { get; set; }
+        [JsonIgnore]
+        public Optional<Stream> Splash
+        {
+            get { return _splash.IsSpecified ? _splash.Value.Stream : null; }
+            set { _splash = value.IsSpecified ? new Image(value.Value) : Optional.Create<Image>(); }
+        }
+        [JsonIgnore]
+        internal Optional<string> SplashHash
+        {
+            get { return _splash.IsSpecified ? _splash.Value.Hash : null; }
+            set { _splash = value.IsSpecified ? new Image(value.Value) : Optional.Create<Image>(); }
+        }
 
         [JsonProperty("afk_channel_id")]
         public Optional<ulong?> AFKChannelId { get; set; }
diff --git a/src/Discord.Net/Entities/Guilds/Guild.cs b/src/Discord.Net/Entities/Guilds/Guild.cs
index 0031fad85..3eed4ce8f 100644
--- a/src/Discord.Net/Entities/Guilds/Guild.cs
+++ b/src/Discord.Net/Entities/Guilds/Guild.cs
@@ -121,6 +121,12 @@ namespace Discord
 
             var args = new ModifyGuildParams();
             func(args);
+
+            if (args.Splash.IsSpecified && _splashId != null)
+                args.SplashHash = _splashId;
+            if (args.Icon.IsSpecified && _iconId != null)
+                args.IconHash = _iconId;
+
             var model = await Discord.ApiClient.ModifyGuildAsync(Id, args).ConfigureAwait(false);
             Update(model, UpdateSource.Rest);
         }
diff --git a/src/Discord.Net/Entities/Users/SelfUser.cs b/src/Discord.Net/Entities/Users/SelfUser.cs
index 0e696aea4..91cd08b92 100644
--- a/src/Discord.Net/Entities/Users/SelfUser.cs
+++ b/src/Discord.Net/Entities/Users/SelfUser.cs
@@ -52,6 +52,8 @@ namespace Discord
 
             if (!args.Username.IsSpecified)
                 args.Username = Username;
+            if (args.Avatar.IsSpecified && _avatarId != null)
+                args.AvatarHash = _avatarId;
 
             var model = await Discord.ApiClient.ModifySelfAsync(args).ConfigureAwait(false);
             Update(model, UpdateSource.Rest);
diff --git a/src/Discord.Net/Entities/Users/User.cs b/src/Discord.Net/Entities/Users/User.cs
index 490128e82..f1f14607c 100644
--- a/src/Discord.Net/Entities/Users/User.cs
+++ b/src/Discord.Net/Entities/Users/User.cs
@@ -7,7 +7,7 @@ namespace Discord
     [DebuggerDisplay("{DebuggerDisplay,nq}")]
     internal class User : SnowflakeEntity, IUser
     {
-        private string _avatarId;
+        protected string _avatarId;
 
         public bool IsBot { get; private set; }
         public string Username { get; private set; }
diff --git a/src/Discord.Net/Net/Converters/DiscordContractResolver.cs b/src/Discord.Net/Net/Converters/DiscordContractResolver.cs
index f30e38cdd..d0f51dc59 100644
--- a/src/Discord.Net/Net/Converters/DiscordContractResolver.cs
+++ b/src/Discord.Net/Net/Converters/DiscordContractResolver.cs
@@ -56,12 +56,14 @@ namespace Discord.Net.Converters
                     property.MemberConverter = converter;
                 }
             }
+            else
+                throw new InvalidOperationException($"{member.DeclaringType.FullName}.{member.Name} is not a property.");
             return property;
         }
 
-        private JsonConverter GetConverter(PropertyInfo propInfo, Type type, TypeInfo typeInfo = null)
+        private JsonConverter GetConverter(MemberInfo member, Type type, TypeInfo typeInfo = null)
         {
-            bool hasInt53 = propInfo.GetCustomAttribute<Int53Attribute>() != null;
+            bool hasInt53 = member.GetCustomAttribute<Int53Attribute>() != null;
 
             //Primitives
             if (!hasInt53)
@@ -81,9 +83,8 @@ namespace Discord.Net.Converters
                 return UserStatusConverter.Instance;
 
             //Special
-            if (type == typeof(Stream) && propInfo.GetCustomAttribute<ImageAttribute>() != null)
-                return ImageConverter.Instance;
-            
+            if (type == typeof(Image))
+                return ImageConverter.Instance;            
 
             if (typeInfo == null) typeInfo = type.GetTypeInfo();
 
diff --git a/src/Discord.Net/Net/Converters/ImageConverter.cs b/src/Discord.Net/Net/Converters/ImageConverter.cs
index 3446d2b2e..88e205688 100644
--- a/src/Discord.Net/Net/Converters/ImageConverter.cs
+++ b/src/Discord.Net/Net/Converters/ImageConverter.cs
@@ -1,6 +1,6 @@
-using Newtonsoft.Json;
+using Discord.API;
+using Newtonsoft.Json;
 using System;
-using System.IO;
 
 namespace Discord.Net.Converters
 {
@@ -19,13 +19,18 @@ namespace Discord.Net.Converters
 
         public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
         {
-            var stream = value as Stream;
+            var image = (Image)value;
 
-            byte[] bytes = new byte[stream.Length - stream.Position];
-            stream.Read(bytes, 0, bytes.Length);
+            if (image.Stream != null)
+            {
+                byte[] bytes = new byte[image.Stream.Length - image.Stream.Position];
+                image.Stream.Read(bytes, 0, bytes.Length);
 
-            string base64 = Convert.ToBase64String(bytes);
-            writer.WriteValue($"data:image/jpeg;base64,{base64}");
+                string base64 = Convert.ToBase64String(bytes);
+                writer.WriteValue($"data:image/jpeg;base64,{base64}");
+            }
+            else if (image.Hash != null)
+                writer.WriteValue(image.Hash);
         }
     }
 }