diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7b5e08638..122b20fd5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,11 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+### Fixed
+
+- [PBLD-279] Fixed an issue where serialization warning would appear upon creating a probuilder shape.
+
 ## [6.0.8] - 2025-11-17
 
 ### Fixed
diff --git a/Runtime/Shapes/Arch.cs b/Runtime/Shapes/Arch.cs
index fb93b6bf3..2f181a491 100644
--- a/Runtime/Shapes/Arch.cs
+++ b/Runtime/Shapes/Arch.cs
@@ -7,6 +7,7 @@ namespace UnityEngine.ProBuilder.Shapes
     /// Represents a basic [arch](../manual/Arch.html) shape.
     /// </summary>
     [Shape("Arch")]
+    [System.Serializable]
     public class Arch : Shape
     {
         /// <summary>
diff --git a/Runtime/Shapes/Cone.cs b/Runtime/Shapes/Cone.cs
index 7093ef79a..34bf1857f 100644
--- a/Runtime/Shapes/Cone.cs
+++ b/Runtime/Shapes/Cone.cs
@@ -7,6 +7,7 @@ namespace UnityEngine.ProBuilder.Shapes
     /// Represents a basic [cone](../manual/Cone.html) shape.
     /// </summary>
     [Shape("Cone")]
+    [System.Serializable]
     public class Cone : Shape
     {
         /// <summary>
@@ -25,7 +26,7 @@ public class Cone : Shape
         /// </summary>
         [SerializeField]
         bool m_Smooth = true;
-        
+
         internal override void SetParametersToBuiltInShape()
         {
             m_NumberOfSides = 8;
diff --git a/Runtime/Shapes/Cube.cs b/Runtime/Shapes/Cube.cs
index 14874c236..47d61c716 100644
--- a/Runtime/Shapes/Cube.cs
+++ b/Runtime/Shapes/Cube.cs
@@ -6,6 +6,7 @@ namespace UnityEngine.ProBuilder.Shapes
     /// Represents a basic [cube](../manual/Cube.html) shape.
     /// </summary>
     [Shape("Cube")]
+    [System.Serializable]
     public class Cube : Shape
     {
         /// <summary>
@@ -25,14 +26,14 @@ public class Cube : Shape
             new Vector3(.5f, .5f, -.5f),        // 6
             new Vector3(-.5f, .5f, -.5f)        // 7
         };
-        
+
         /// <summary>
         /// Defines a set of triangles forming a cube with reference to the k_CubeVertices array.
         /// </summary>
         static readonly int[] k_CubeTriangles = new int[] {
             0, 1, 4, 5, 1, 2, 5, 6, 2, 3, 6, 7, 3, 0, 7, 4, 4, 5, 7, 6, 3, 2, 0, 1
         };
-        
+
         internal override void SetParametersToBuiltInShape() { }
 
         /// <inheritdoc/>
@@ -47,14 +48,14 @@ public override Bounds RebuildMesh(ProBuilderMesh mesh, Vector3 size, Quaternion
 
             for (int i = 0; i < k_CubeTriangles.Length; i++)
                 points[i] = rotation * Vector3.Scale(k_CubeVertices[k_CubeTriangles[i]], Math.Abs(size));
-            
+
             mesh.GeometryWithPoints(points);
-            
+
             UvUnwrapping.SetAutoUV(mesh, mesh.facesInternal, true);
             foreach (var face in mesh.facesInternal)
                 face.uv = new AutoUnwrapSettings(face.uv) { anchor = AutoUnwrapSettings.Anchor.UpperLeft};
             mesh.RefreshUV(mesh.faces);
-            
+
             return mesh.mesh.bounds;
         }
     }
diff --git a/Runtime/Shapes/Cylinder.cs b/Runtime/Shapes/Cylinder.cs
index 57f2f6404..8c1acf197 100644
--- a/Runtime/Shapes/Cylinder.cs
+++ b/Runtime/Shapes/Cylinder.cs
@@ -6,6 +6,7 @@ namespace UnityEngine.ProBuilder.Shapes
     /// Represents a basic [cylinder](../manual/Cylinder.html) shape.
     /// </summary>
     [Shape("Cylinder")]
+    [System.Serializable]
     public class Cylinder : Shape
     {
         /// <summary>
@@ -30,7 +31,7 @@ public class Cylinder : Shape
         /// </summary>
         [SerializeField]
         bool m_Smooth = true;
-        
+
         internal override void SetParametersToBuiltInShape()
         {
             m_AxisDivisions = 8;
diff --git a/Runtime/Shapes/Door.cs b/Runtime/Shapes/Door.cs
index 32f396014..78bdaa6be 100644
--- a/Runtime/Shapes/Door.cs
+++ b/Runtime/Shapes/Door.cs
@@ -7,6 +7,7 @@ namespace UnityEngine.ProBuilder.Shapes
     /// Represents a basic [door](../manual/Door.html) shape.
     /// </summary>
     [Shape("Door")]
+    [System.Serializable]
     public class Door : Shape
     {
         /// <summary>
@@ -30,7 +31,7 @@ internal override void SetParametersToBuiltInShape()
             m_DoorHeight = 0.5f;
             m_LegWidth = 0.75f;
         }
-        
+
         /// <inheritdoc/>
         public override void CopyShape(Shape shape)
         {
diff --git a/Runtime/Shapes/Pipe.cs b/Runtime/Shapes/Pipe.cs
index 69c39a91b..bed4a5a5b 100644
--- a/Runtime/Shapes/Pipe.cs
+++ b/Runtime/Shapes/Pipe.cs
@@ -7,6 +7,7 @@ namespace UnityEngine.ProBuilder.Shapes
     /// Represents a basic [pipe](../manual/Pipe.html) shape.
     /// </summary>
     [Shape("Pipe")]
+    [System.Serializable]
     public class Pipe : Shape
     {
         /// <summary>
@@ -39,7 +40,7 @@ public class Pipe : Shape
         /// </summary>
         [SerializeField]
         bool m_Smooth = true;
-        
+
         internal override void SetParametersToBuiltInShape()
         {
             m_Thickness = 0.25f;
diff --git a/Runtime/Shapes/Plane.cs b/Runtime/Shapes/Plane.cs
index 6c3eb2470..0d5a9919c 100644
--- a/Runtime/Shapes/Plane.cs
+++ b/Runtime/Shapes/Plane.cs
@@ -6,6 +6,7 @@ namespace UnityEngine.ProBuilder.Shapes
     /// Represents a basic [plane](../manual/Plane.html) shape.
     /// </summary>
     [Shape("Plane")]
+    [System.Serializable]
     public class Plane : Shape
     {
         /// <summary>
diff --git a/Runtime/Shapes/Prism.cs b/Runtime/Shapes/Prism.cs
index 45986a756..f8441e66c 100644
--- a/Runtime/Shapes/Prism.cs
+++ b/Runtime/Shapes/Prism.cs
@@ -6,10 +6,11 @@ namespace UnityEngine.ProBuilder.Shapes
     /// Represents a basic [prism](../manual/Prism.html) shape.
     /// </summary>
     [Shape("Prism")]
+    [System.Serializable]
     public class Prism : Shape
     {
         internal override void SetParametersToBuiltInShape() { }
-        
+
         /// <inheritdoc/>
         public override void CopyShape(Shape shape) {}
 
diff --git a/Runtime/Shapes/Sphere.cs b/Runtime/Shapes/Sphere.cs
index d564e6066..f1ae8db15 100644
--- a/Runtime/Shapes/Sphere.cs
+++ b/Runtime/Shapes/Sphere.cs
@@ -6,6 +6,7 @@ namespace UnityEngine.ProBuilder.Shapes
     /// Represents a basic [sphere](../manual/Sphere.html) shape.
     /// </summary>
     [Shape("Sphere")]
+    [System.Serializable]
     public class Sphere : Shape
     {
         static readonly Vector3[] k_IcosphereVertices = new Vector3[12]
@@ -67,7 +68,7 @@ public class Sphere : Shape
         int m_BottomMostVertexIndex = 0;
 
         /// <summary>
-        /// Determines whether to smooth the edges of the polygons. 
+        /// Determines whether to smooth the edges of the polygons.
         /// This property is enabled by default.
         /// </summary>
         [SerializeField]
@@ -78,7 +79,7 @@ internal override void SetParametersToBuiltInShape()
             m_Subdivisions = 2;
             m_Smooth = false;
         }
-        
+
         /// <inheritdoc/>
         public override void CopyShape(Shape shape)
         {
diff --git a/Runtime/Shapes/Sprite.cs b/Runtime/Shapes/Sprite.cs
index 4bdb31627..d58fe14bb 100644
--- a/Runtime/Shapes/Sprite.cs
+++ b/Runtime/Shapes/Sprite.cs
@@ -6,10 +6,11 @@ namespace UnityEngine.ProBuilder.Shapes
     /// Represents a basic [sprite](../manual/Sprite.html) (a single-unit plane shape).
     /// </summary>
     [Shape("Sprite")]
+    [System.Serializable]
     public class Sprite : Shape
     {
         internal override void SetParametersToBuiltInShape() { }
-        
+
         /// <inheritdoc/>
         public override void CopyShape(Shape shape) {}
 
diff --git a/Runtime/Shapes/Stairs.cs b/Runtime/Shapes/Stairs.cs
index ed027873d..67fc8afe3 100644
--- a/Runtime/Shapes/Stairs.cs
+++ b/Runtime/Shapes/Stairs.cs
@@ -23,6 +23,7 @@ enum StepGenerationType
     /// Represents a basic [stairs](../manual/Stairs.html) shape.
     /// </summary>
     [Shape("Stairs")]
+    [System.Serializable]
     public class Stairs : Shape
     {
         /// <summary>
@@ -51,12 +52,12 @@ public class Stairs : Shape
         [Range(1, 256)]
         [SerializeField]
         int m_StepsCount = 10;
-        internal int stepsCount 
+        internal int stepsCount
         {
             get => m_StepsCount;
             set => m_StepsCount = value;
         }
-        
+
         /// <summary>
         /// Determines whether to force every step to be the exactly the same height. If disabled,
         /// the height of the last step is smaller than the others depending on the remaining height.
@@ -78,7 +79,7 @@ internal int stepsCount
         [SerializeField]
         float m_Circumference = 0f;
 
-        internal float circumference 
+        internal float circumference
         {
             get => m_Circumference;
             set => m_Circumference = value;
@@ -103,7 +104,7 @@ public bool sides
 
         [SerializeField, Min(0f)]
         float m_InnerRadius;
-        internal float innerRadius 
+        internal float innerRadius
         {
             get => m_InnerRadius;
             set => m_InnerRadius = value;
diff --git a/Runtime/Shapes/Torus.cs b/Runtime/Shapes/Torus.cs
index b885c233e..74f29a44e 100644
--- a/Runtime/Shapes/Torus.cs
+++ b/Runtime/Shapes/Torus.cs
@@ -8,6 +8,7 @@ namespace UnityEngine.ProBuilder.Shapes
     /// Represents a basic [torus](../manual/Torus.html) shape.
     /// </summary>
     [Shape("Torus")]
+    [System.Serializable]
     public class Torus : Shape
     {
         /// <summary>