diff --git a/include/suboptimal/autodiff/Expression.h b/include/suboptimal/autodiff/Expression.h
index a3bc557..5de162d 100644
--- a/include/suboptimal/autodiff/Expression.h
+++ b/include/suboptimal/autodiff/Expression.h
@@ -63,11 +63,11 @@ struct Expression {
 
   Expression(const Expression& other) = delete;
 
-  Expression(Expression&& other) = default;
+  Expression(Expression&& other) = delete;
 
   Expression& operator=(const Expression& other) = delete;
 
-  Expression& operator=(Expression&& other) = default;
+  Expression& operator=(Expression&& other) = delete;
 
   ~Expression() = default;
 
diff --git a/include/suboptimal/autodiff/Variable.h b/include/suboptimal/autodiff/Variable.h
index 9abc09c..9c1f295 100644
--- a/include/suboptimal/autodiff/Variable.h
+++ b/include/suboptimal/autodiff/Variable.h
@@ -31,7 +31,8 @@ using Matrix3v = Eigen::Matrix3<Variable>;
 using Matrix4v = Eigen::Matrix4<Variable>;
 
 /**
- * An autodiff variable. Essentially just a nicer wrapper around Expression
+ * An autodiff variable. Basically a nicer wrapper around Expression. Unlike Expression, a Variable is safe to copy and
+ * move around.
  */
 struct Variable {
   ExpressionPtr expr = std::make_shared<Expression>(0.0, Linearity::Linear);