diff --git a/Assets/Scripts/Intrepid/Gameplay/Prototyping/ContactCubeModelPrototype.cs b/Assets/Scripts/Intrepid/Gameplay/Prototyping/ContactCubeModelPrototype.cs
index 6f103b2..5b32b34 100644
--- a/Assets/Scripts/Intrepid/Gameplay/Prototyping/ContactCubeModelPrototype.cs
+++ b/Assets/Scripts/Intrepid/Gameplay/Prototyping/ContactCubeModelPrototype.cs
@@ -27,19 +27,19 @@ namespace Intrepid.Gameplay.Prototyping
         public int SizeX
         {
             get => sizeX;
-            set => sizeX = value;
+            set => sizeX = Mathf.Max(0, value);
         }
 
         public int SizeY
         {
             get => sizeY;
-            set => sizeY = value;
+            set => sizeY = Mathf.Max(0, value);
         }
 
         public int SizeZ
         {
             get => sizeZ;
-            set => sizeZ = value;
+            set => sizeZ = Mathf.Max(0, value);
         }
 
         public BoxCollider BoxCollider => boxCollider;
diff --git a/Assets/Scripts/Intrepid/Gameplay/Prototyping/GroundRampModelPrototype.cs b/Assets/Scripts/Intrepid/Gameplay/Prototyping/GroundRampModelPrototype.cs
index 03caa28..bbdc188 100644
--- a/Assets/Scripts/Intrepid/Gameplay/Prototyping/GroundRampModelPrototype.cs
+++ b/Assets/Scripts/Intrepid/Gameplay/Prototyping/GroundRampModelPrototype.cs
@@ -26,13 +26,13 @@ namespace Intrepid.Gameplay.Prototyping
         public int SizeX
         {
             get => sizeX;
-            set => sizeX = value;
+            set => sizeX = Mathf.Max(0, value);
         }
 
         public int SizeZ
         {
             get => sizeZ;
-            set => sizeZ = value;
+            set => sizeZ = Mathf.Max(0, value);
         }
 
         public BoxCollider BoxCollider => boxCollider;
diff --git a/Assets/Scripts/Intrepid/Gameplay/Prototyping/GroundSlabModelPrototype.cs b/Assets/Scripts/Intrepid/Gameplay/Prototyping/GroundSlabModelPrototype.cs
index f6a634a..53b0c29 100644
--- a/Assets/Scripts/Intrepid/Gameplay/Prototyping/GroundSlabModelPrototype.cs
+++ b/Assets/Scripts/Intrepid/Gameplay/Prototyping/GroundSlabModelPrototype.cs
@@ -23,13 +23,13 @@ namespace Intrepid.Gameplay.Prototyping
         public int SizeX
         {
             get => sizeX;
-            set => sizeX = value;
+            set => sizeX = Mathf.Max(0, value);
         }
 
         public int SizeZ
         {
             get => sizeZ;
-            set => sizeZ = value;
+            set => sizeZ = Mathf.Max(0, value);
         }
 
         public BoxCollider BoxCollider => boxCollider;