diff --git a/OSCADSharp/OSCADSharp.UnitTests/Solids/CylinderTests.cs b/OSCADSharp/OSCADSharp.UnitTests/Solids/CylinderTests.cs
index b060287..474ebb5 100644
--- a/OSCADSharp/OSCADSharp.UnitTests/Solids/CylinderTests.cs
+++ b/OSCADSharp/OSCADSharp.UnitTests/Solids/CylinderTests.cs
@@ -222,5 +222,22 @@ namespace OSCADSharp.UnitTests
             Assert.IsTrue(script.Contains("d2 = mainColumn"));
             Assert.IsTrue(script.Contains("h = overallHeight"));
         }
+
+        [TestMethod]
+        public void Cylinder_NegationOnConstructorVariablesProvidesExpectedOutput()
+        {
+            Variable wheelThickness = new Variable("wheelThickness", Inches.Eigth + Inches.Sixteenth);
+            Variable wheelDiameter = new Variable("wheelDiameter", Inches.ToMillimeters(1.5));
+            Variable wheelHoleDiameter = new Variable("wheelHoleDiameter", Inches.Quarter);
+
+            OSCADObject cyl = new Cylinder(wheelHoleDiameter - 1, wheelHoleDiameter - 1, wheelThickness + 2)
+                    .Translate(0, -wheelDiameter / 2 + wheelHoleDiameter / 2, 0);
+
+            string script = cyl.ToString();
+
+            Assert.IsTrue(script.Contains("translate(v = [0, -wheelDiameter / 2 + wheelHoleDiameter / 2, 0])"));
+            Assert.IsTrue(script.Contains("cylinder(center = false, d1 = wheelHoleDiameter - 1, d2 = wheelHoleDiameter - 1, h = wheelThickness + 2);"));
+
+        }
     }
 }
diff --git a/OSCADSharp/OSCADSharp/Scripting/Variable.cs b/OSCADSharp/OSCADSharp/Scripting/Variable.cs
index 695c627..6ce1486 100644
--- a/OSCADSharp/OSCADSharp/Scripting/Variable.cs
+++ b/OSCADSharp/OSCADSharp/Scripting/Variable.cs
@@ -113,6 +113,27 @@ namespace OSCADSharp.Scripting
             return new Variable(String.Format("{0} - {1}", left.Name, right.Name), VariableCalculator.Subtract(left.Value, right.Value));
         }
 
+        /// <summary>
+        /// Numerical negation on a variable
+        /// </summary>
+        /// <param name="right"></param>
+        /// <returns></returns>
+        public static Variable operator -(Variable right)
+        {
+            object value = null;
+
+            if (VariableCalculator.IsNumeric(right.Value))
+            {
+                value = -Convert.ToDouble(right.Value);
+            }            
+            else if(VariableCalculator.IsVector(right.Value))
+            {
+                value = ((Vector3)right.Value).Negate();
+            }
+
+            return new Variable(String.Format("-{0}", right.Name), value);
+        }
+
         /// <summary>
         /// Subtracts a value from a variable
         /// </summary>