diff --git a/Tomlet/Models/TomlDocument.cs b/Tomlet/Models/TomlDocument.cs
index cdf8118..c26cc5e 100644
--- a/Tomlet/Models/TomlDocument.cs
+++ b/Tomlet/Models/TomlDocument.cs
@@ -1,4 +1,5 @@
 using System.Text;
+using Tomlet.Extensions;
 
 namespace Tomlet.Models
 {
@@ -16,9 +17,9 @@ internal TomlDocument()
 
         internal TomlDocument(TomlTable from)
         {
-            foreach (var key in from.Keys)
+            foreach (var (key, value) in from)
             {
-                PutValue(key, from.GetValue(key));
+                PutValue(TomlKeyUtils.FullStringToProperKey(key), value);
             }
         }