diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7ecbba24a..112aab2ef 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 - gar : fix missing move assignment operator in `LqrProblemTpl`
+- Fix C++20 support. Fix `consteval` compilation errors related to fmt
 
 ### Changed
 
diff --git a/include/aligator/modelling/centroidal/angular-acceleration.hpp b/include/aligator/modelling/centroidal/angular-acceleration.hpp
index 98e421f53..46c369c1c 100644
--- a/include/aligator/modelling/centroidal/angular-acceleration.hpp
+++ b/include/aligator/modelling/centroidal/angular-acceleration.hpp
@@ -41,9 +41,8 @@ struct AngularAccelerationResidualTpl : StageFunctionTpl<_Scalar> {
       , force_size_(force_size) {
     if (contact_map.size_ != nk_) {
       ALIGATOR_DOMAIN_ERROR(
-          fmt::format("Contact ids and nk should be the same: now "
-                      "({} and {}).",
-                      contact_map.size_, nk_));
+          "Contact ids and nk should be the same ({:d} and {:d}).",
+          contact_map.size_, nk_);
     }
   }
 
diff --git a/include/aligator/modelling/centroidal/centroidal-acceleration.hpp b/include/aligator/modelling/centroidal/centroidal-acceleration.hpp
index ab566a45b..09e4c4118 100644
--- a/include/aligator/modelling/centroidal/centroidal-acceleration.hpp
+++ b/include/aligator/modelling/centroidal/centroidal-acceleration.hpp
@@ -41,9 +41,8 @@ struct CentroidalAccelerationResidualTpl : StageFunctionTpl<_Scalar> {
       , force_size_(force_size) {
     if (contact_map.size_ != nk_) {
       ALIGATOR_DOMAIN_ERROR(
-          fmt::format("Contact ids and nk should be the same: now "
-                      "({} and {}).",
-                      contact_map.size_, nk_));
+          "Contact ids and nk should be the same ({:d} and {:d}).",
+          contact_map.size_, nk_);
     }
   }
 
diff --git a/include/aligator/modelling/contact-map.hpp b/include/aligator/modelling/contact-map.hpp
index c0f69d307..1471be5cf 100644
--- a/include/aligator/modelling/contact-map.hpp
+++ b/include/aligator/modelling/contact-map.hpp
@@ -18,9 +18,9 @@ template <typename _Scalar> struct ContactMapTpl {
       , contact_poses_(contact_poses) {
     if (contact_states.size() != contact_poses.size()) {
       ALIGATOR_DOMAIN_ERROR(
-          fmt::format("contact_states and contact_poses should have same size, "
-                      "currently ({} and {}).",
-                      contact_states.size(), contact_poses.size()));
+          "Contact_states and contact_poses should have same size, "
+          "currently ({:d} and {:d}).",
+          contact_states.size(), contact_poses.size());
     }
     size_ = contact_states_.size();
   }
diff --git a/include/aligator/modelling/costs/sum-of-costs.hxx b/include/aligator/modelling/costs/sum-of-costs.hxx
index 86760ed71..624bd726c 100644
--- a/include/aligator/modelling/costs/sum-of-costs.hxx
+++ b/include/aligator/modelling/costs/sum-of-costs.hxx
@@ -10,19 +10,16 @@ CostStackTpl<Scalar>::CostStackTpl(xyz::polymorphic<Manifold> space,
                                    const std::vector<Scalar> &weights)
     : CostBase(space, nu) {
   if (comps.size() != weights.size()) {
-    auto msg = fmt::format(
+    ALIGATOR_RUNTIME_ERROR(
         "Inconsistent number of components ({:d}) and weights ({:d}).",
         comps.size(), weights.size());
-    ALIGATOR_RUNTIME_ERROR(msg);
   } else {
     for (std::size_t i = 0; i < comps.size(); i++) {
       if (!this->checkDimension(*comps[i])) {
-        auto msg = fmt::format("Component #{:d} has wrong input dimensions "
-                               "({:d}, {:d}) (expected "
-                               "({:d}, {:d}))",
+        ALIGATOR_RUNTIME_ERROR("Component #{:d} has wrong input dimensions "
+                               "({:d}, {:d}) (expected ({:d}, {:d}))",
                                i, comps[i]->ndx(), comps[i]->nu, this->ndx(),
                                this->nu);
-        ALIGATOR_RUNTIME_ERROR(msg);
       }
     }
 
diff --git a/include/aligator/modelling/dynamics/multibody-constraint-fwd.hxx b/include/aligator/modelling/dynamics/multibody-constraint-fwd.hxx
index 31f56f250..832c69ebb 100644
--- a/include/aligator/modelling/dynamics/multibody-constraint-fwd.hxx
+++ b/include/aligator/modelling/dynamics/multibody-constraint-fwd.hxx
@@ -21,9 +21,9 @@ MultibodyConstraintFwdDynamicsTpl<Scalar>::MultibodyConstraintFwdDynamicsTpl(
   const int nv = state.getModel().nv;
   if (nv != actuation.rows()) {
     ALIGATOR_DOMAIN_ERROR(
-        fmt::format("actuation matrix should have number of rows = pinocchio "
-                    "model nv ({} and {}).",
-                    actuation.rows(), nv));
+        "Actuation matrix should have number of rows = pinocchio "
+        "model nv ({} and {}).",
+        actuation.rows(), nv);
   }
 }
 
diff --git a/include/aligator/modelling/dynamics/multibody-free-fwd.hxx b/include/aligator/modelling/dynamics/multibody-free-fwd.hxx
index 514e6bd3a..05d11b670 100644
--- a/include/aligator/modelling/dynamics/multibody-free-fwd.hxx
+++ b/include/aligator/modelling/dynamics/multibody-free-fwd.hxx
@@ -20,9 +20,9 @@ MultibodyFreeFwdDynamicsTpl<Scalar>::MultibodyFreeFwdDynamicsTpl(
   const int nv = space().getModel().nv;
   if (nv != actuation.rows()) {
     ALIGATOR_DOMAIN_ERROR(
-        fmt::format("actuation matrix should have number of rows = pinocchio "
-                    "model nv ({} and {}).",
-                    actuation.rows(), nv));
+        "Actuation matrix should have number of rows = pinocchio "
+        "model nv ({} and {}).",
+        actuation.rows(), nv);
   }
   act_matrix_rank = lu_decomp_.rank();
 }
diff --git a/include/aligator/modelling/multibody/centroidal-momentum-derivative.hxx b/include/aligator/modelling/multibody/centroidal-momentum-derivative.hxx
index 911b6c6e5..1bf907cd7 100644
--- a/include/aligator/modelling/multibody/centroidal-momentum-derivative.hxx
+++ b/include/aligator/modelling/multibody/centroidal-momentum-derivative.hxx
@@ -25,9 +25,8 @@ CentroidalMomentumDerivativeResidualTpl<Scalar>::
   mass_ = pinocchio::computeTotalMass(model);
   if (contact_ids_.size() != contact_states_.size()) {
     ALIGATOR_DOMAIN_ERROR(
-        fmt::format("contact_ids and contact_states should have same size: "
-                    "now ({} and {}).",
-                    contact_ids_.size(), contact_states_.size()));
+        "contact_ids and contact_states should have same size ({:d} and {:d}).",
+        contact_ids_.size(), contact_states_.size());
   }
 }
 
diff --git a/include/aligator/modelling/multibody/contact-force.hpp b/include/aligator/modelling/multibody/contact-force.hpp
index 1b2eba86f..c5bba05cc 100644
--- a/include/aligator/modelling/multibody/contact-force.hpp
+++ b/include/aligator/modelling/multibody/contact-force.hpp
@@ -54,10 +54,9 @@ struct ContactForceResidualTpl : StageFunctionTpl<_Scalar> {
       , fref_(fref)
       , force_size_(fref.size()) {
     if (model.nv != actuation.rows()) {
-      ALIGATOR_DOMAIN_ERROR(
-          fmt::format("actuation matrix should have number of rows = pinocchio "
-                      "model nv ({} and {}).",
-                      actuation.rows(), model.nv));
+      ALIGATOR_DOMAIN_ERROR("Actuation matrix should have number of rows = "
+                            "model.nv ({:d} and {:d}).",
+                            actuation.rows(), model.nv);
     }
     contact_id_ = -1;
     for (std::size_t i = 0; i < constraint_models.size(); i++) {
diff --git a/include/aligator/modelling/multibody/multibody-friction-cone.hpp b/include/aligator/modelling/multibody/multibody-friction-cone.hpp
index b36c14041..db18a7f9a 100644
--- a/include/aligator/modelling/multibody/multibody-friction-cone.hpp
+++ b/include/aligator/modelling/multibody/multibody-friction-cone.hpp
@@ -50,10 +50,9 @@ struct MultibodyFrictionConeResidualTpl : StageFunctionTpl<_Scalar> {
       , prox_settings_(prox_settings)
       , mu_(mu) {
     if (model.nv != actuation.rows()) {
-      ALIGATOR_DOMAIN_ERROR(
-          fmt::format("actuation matrix should have number of rows = pinocchio "
-                      "model nv ({} and {}).",
-                      actuation.rows(), model.nv));
+      ALIGATOR_DOMAIN_ERROR("Actuation matrix should have number of rows = "
+                            "model.nv ({:d} and {:d}).",
+                            actuation.rows(), model.nv);
     }
     contact_id_ = -1;
     for (std::size_t i = 0; i < constraint_models.size(); i++) {
diff --git a/include/aligator/modelling/multibody/multibody-wrench-cone.hpp b/include/aligator/modelling/multibody/multibody-wrench-cone.hpp
index 15c8fa3ac..e157c71b7 100644
--- a/include/aligator/modelling/multibody/multibody-wrench-cone.hpp
+++ b/include/aligator/modelling/multibody/multibody-wrench-cone.hpp
@@ -57,10 +57,9 @@ struct MultibodyWrenchConeResidualTpl : StageFunctionTpl<_Scalar> {
       , hL_(half_length)
       , hW_(half_width) {
     if (model.nv != actuation.rows()) {
-      ALIGATOR_DOMAIN_ERROR(
-          fmt::format("actuation matrix should have number of rows = pinocchio "
-                      "model nv ({} and {}).",
-                      actuation.rows(), model.nv));
+      ALIGATOR_DOMAIN_ERROR("Actuation matrix should have number of rows = "
+                            "model.nv ({:d} and {:d}).",
+                            actuation.rows(), model.nv);
     }
     contact_id_ = -1;
     for (std::size_t i = 0; i < constraint_models.size(); i++) {
diff --git a/src/utils/logger.cpp b/src/utils/logger.cpp
index 73b41e63c..cbd2b1d05 100644
--- a/src/utils/logger.cpp
+++ b/src/utils/logger.cpp
@@ -40,10 +40,13 @@ void Logger::finish(bool conv) {
   if (!active)
     return;
 
-  auto ts = fmt::fg(conv ? fmt::color::dodger_blue : fmt::color::red);
-  const char *msg = conv ? "Successfully converged." : "Convergence failure.";
-  fmt::print(ts, msg);
-  fmt::print("\n");
+  fmt::text_style ts =
+      fmt::fg(conv ? fmt::color::dodger_blue : fmt::color::red);
+  if (conv) {
+    fmt::print(ts, "Successfully converged\n");
+  } else {
+    fmt::print(ts, "Convergence failure\n");
+  }
 }
 
 void Logger::addColumn(std::string_view name, uint width,
@@ -55,12 +58,12 @@ void Logger::addColumn(std::string_view name, uint width,
 
 void Logger::addEntry(std::string_view name, double val) {
   const auto spec = m_colSpecs[name];
-  m_currentLine[name] = fmt::format(spec.second, val, spec.first);
+  m_currentLine[name] = fmt::format(fmt::runtime(spec.second), val, spec.first);
 }
 
 void Logger::addEntry(std::string_view name, size_t val) {
   const auto spec = m_colSpecs[name];
-  m_currentLine[name] = fmt::format(spec.second, val, spec.first);
+  m_currentLine[name] = fmt::format(fmt::runtime(spec.second), val, spec.first);
 }
 
 } // namespace aligator