diff --git a/src/variables/macros.rs b/src/variables/macros.rs
index 4e3db1b..61b6997 100644
--- a/src/variables/macros.rs
+++ b/src/variables/macros.rs
@@ -160,23 +160,8 @@ macro_rules! test_lie {
 }
 
 #[macro_export]
-macro_rules! impl_safe_variable {
-($($var:ident $(< $num:literal >)? ),* $(,)?) => {
-        $(
-            #[cfg_attr(feature = "serde", typetag::serde)]
-            impl $crate::variables::VariableSafe for $var$(< $num >)? {
-                fn clone_box(&self) -> Box<dyn $crate::variables::VariableSafe> {
-                    Box::new((*self).clone())
-                }
-
-                fn dim(&self) -> usize {
-                    $crate::variables::Variable::dim(self)
-                }
-
-                fn oplus_mut(&mut self, delta: VectorViewX) {
-                    *self = self.oplus(delta);
-                }
-            }
-        )*
-    };
+macro_rules! tag_variable {
+    ($($ty:ty),* $(,)?) => {$(
+        $crate::register_typetag!($crate::variables::VariableSafe, $ty);
+    )*};
 }
diff --git a/src/variables/se2.rs b/src/variables/se2.rs
index 391cbce..8351807 100644
--- a/src/variables/se2.rs
+++ b/src/variables/se2.rs
@@ -3,7 +3,6 @@ use std::{fmt, ops};
 use super::VectorVar2;
 use crate::{
     dtype,
-    impl_safe_variable,
     linalg::{
         dvector,
         AllocatorBuffer,
@@ -24,10 +23,11 @@ use crate::{
         VectorViewX,
         VectorX,
     },
+    tag_variable,
     variables::{MatrixLieGroup, Variable, SO2},
 };
 
-impl_safe_variable!(SE2);
+tag_variable!(SE2);
 
 #[derive(Clone)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
diff --git a/src/variables/se3.rs b/src/variables/se3.rs
index b21679a..a4b0ce9 100644
--- a/src/variables/se3.rs
+++ b/src/variables/se3.rs
@@ -3,7 +3,6 @@ use std::{fmt, ops};
 use super::VectorVar3;
 use crate::{
     dtype,
-    impl_safe_variable,
     linalg::{
         AllocatorBuffer,
         Const,
@@ -24,10 +23,11 @@ use crate::{
         VectorViewX,
         VectorX,
     },
+    tag_variable,
     variables::{MatrixLieGroup, Variable, SO3},
 };
 
-impl_safe_variable!(SE3);
+tag_variable!(SE3);
 
 #[derive(Clone, Debug)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
diff --git a/src/variables/so2.rs b/src/variables/so2.rs
index 4a4ea92..cfd20fc 100644
--- a/src/variables/so2.rs
+++ b/src/variables/so2.rs
@@ -2,7 +2,6 @@ use std::{fmt, ops};
 
 use crate::{
     dtype,
-    impl_safe_variable,
     linalg::{
         dvector,
         AllocatorBuffer,
@@ -24,10 +23,11 @@ use crate::{
         VectorViewX,
         VectorX,
     },
+    tag_variable,
     variables::{MatrixLieGroup, Variable},
 };
 
-impl_safe_variable!(SO2);
+tag_variable!(SO2);
 
 #[derive(Clone)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
diff --git a/src/variables/so3.rs b/src/variables/so3.rs
index 08c1e62..14f0e49 100644
--- a/src/variables/so3.rs
+++ b/src/variables/so3.rs
@@ -3,7 +3,6 @@ use std::{fmt, ops};
 use super::VectorVar4;
 use crate::{
     dtype,
-    impl_safe_variable,
     linalg::{
         dvector,
         AllocatorBuffer,
@@ -23,10 +22,11 @@ use crate::{
         VectorViewX,
         VectorX,
     },
+    tag_variable,
     variables::{MatrixLieGroup, Variable},
 };
 
-impl_safe_variable!(SO3);
+tag_variable!(SO3);
 
 #[derive(Clone)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
diff --git a/src/variables/traits.rs b/src/variables/traits.rs
index 87f7ef3..5b57416 100644
--- a/src/variables/traits.rs
+++ b/src/variables/traits.rs
@@ -100,6 +100,34 @@ pub trait VariableSafe: Debug + Display + Downcast {
     fn oplus_mut(&mut self, delta: VectorViewX);
 }
 
+impl<
+        #[cfg(not(feature = "serde"))] T: Variable + 'static,
+        #[cfg(feature = "serde")] T: Variable + 'static + crate::serde::Tagged,
+    > VariableSafe for T
+{
+    fn clone_box(&self) -> Box<dyn VariableSafe> {
+        Box::new((*self).clone())
+    }
+
+    fn dim(&self) -> usize {
+        self.dim()
+    }
+
+    fn oplus_mut(&mut self, delta: VectorViewX) {
+        *self = self.oplus(delta);
+    }
+
+    #[doc(hidden)]
+    #[cfg(feature = "serde")]
+    fn typetag_name(&self) -> &'static str {
+        Self::TAG
+    }
+
+    #[doc(hidden)]
+    #[cfg(feature = "serde")]
+    fn typetag_deserialize(&self) {}
+}
+
 pub trait VariableUmbrella<D: Numeric = dtype>:
     VariableSafe + Variable<D, Alias<D> = Self>
 {
diff --git a/src/variables/vector.rs b/src/variables/vector.rs
index 9e8ee73..9bcae2a 100644
--- a/src/variables/vector.rs
+++ b/src/variables/vector.rs
@@ -5,7 +5,6 @@ use std::{
 
 use crate::{
     dtype,
-    impl_safe_variable,
     linalg::{
         AllocatorBuffer,
         Const,
@@ -19,10 +18,11 @@ use crate::{
         VectorViewX,
         VectorX,
     },
+    tag_variable,
     variables::Variable,
 };
 
-impl_safe_variable!(
+tag_variable!(
     VectorVar<1>,
     VectorVar<2>,
     VectorVar<3>,