diff --git a/Assets/LDtkUnity/CHANGELOG.md b/Assets/LDtkUnity/CHANGELOG.md
index 85edc5075..1bbc56cf8 100644
--- a/Assets/LDtkUnity/CHANGELOG.md
+++ b/Assets/LDtkUnity/CHANGELOG.md
@@ -18,6 +18,8 @@
 - Updated docs to instruct that a texture should be RGBA32 compression
 - Made the LDtkComponentLayer ordered before the LDtkIid component 
 - Fixed a possible exception during initialization of LDtkFields
+- Fixed a deserialize exception when making a blank LDtk project whereby `defaultEntityWidth` and `defaultEntityHeight` are null when they shouldn't be
+  - This is a temporary measure and LDtk will fix this problem for LDtk 1.5 
 
 ### Breaking Changes
 - Removed the "De-parent in Runtime" feature from the project importer
diff --git a/Assets/LDtkUnity/Runtime/Data/Extensions/LdtkJson.cs b/Assets/LDtkUnity/Runtime/Data/Extensions/LdtkJson.cs
index 6e521b711..4574b9bfa 100644
--- a/Assets/LDtkUnity/Runtime/Data/Extensions/LdtkJson.cs
+++ b/Assets/LDtkUnity/Runtime/Data/Extensions/LdtkJson.cs
@@ -24,7 +24,7 @@ public partial class LdtkJson : ILDtkIid
         /// <value>
         /// Default size for new entities
         /// </value>
-        [IgnoreDataMember] public Vector2Int UnityDefaultEntitySize => new Vector2Int(DefaultEntityWidth, DefaultEntityHeight);
+        [IgnoreDataMember] public Vector2Int UnityDefaultEntitySize => DefaultEntityWidth != null && DefaultEntityHeight != null ? new Vector2Int(DefaultEntityWidth.Value, DefaultEntityHeight.Value) : Vector2Int.zero;
         
         /// <value>
         /// Default pivot (0 to 1) for new entities
diff --git a/Assets/LDtkUnity/Runtime/Data/Schema/LdtkJson.cs b/Assets/LDtkUnity/Runtime/Data/Schema/LdtkJson.cs
index db3d2921a..f1bec3ce2 100644
--- a/Assets/LDtkUnity/Runtime/Data/Schema/LdtkJson.cs
+++ b/Assets/LDtkUnity/Runtime/Data/Schema/LdtkJson.cs
@@ -76,13 +76,13 @@ public partial class LdtkJson
         /// Default height for new entities
         /// </summary>
         [DataMember(Name = "defaultEntityHeight")]
-        public int DefaultEntityHeight { get; set; }
+        public int? DefaultEntityHeight { get; set; }
 
         /// <summary>
         /// Default width for new entities
         /// </summary>
         [DataMember(Name = "defaultEntityWidth")]
-        public int DefaultEntityWidth { get; set; }
+        public int? DefaultEntityWidth { get; set; }
 
         /// <summary>
         /// Default grid size for new layers