diff --git a/include/amici/abstract_model.h b/include/amici/abstract_model.h
index d80a213e9f..56b54eaceb 100644
--- a/include/amici/abstract_model.h
+++ b/include/amici/abstract_model.h
@@ -357,12 +357,10 @@ class AbstractModel {
      * @param k constant vector
      * @param h Heaviside vector
      * @param w repeating elements vector
-     * @param dwdx Recurring terms in xdot, state derivative
      */
     virtual void fdydx(
         realtype* dydx, realtype t, realtype const* x, realtype const* p,
-        realtype const* k, realtype const* h, realtype const* w,
-        realtype const* dwdx
+        realtype const* k, realtype const* h, realtype const* w
     );
 
     /**
diff --git a/models/model_calvetti_py/dydx.cpp b/models/model_calvetti_py/dydx.cpp
index 8bacfcc05d..23280d05fa 100644
--- a/models/model_calvetti_py/dydx.cpp
+++ b/models/model_calvetti_py/dydx.cpp
@@ -6,12 +6,11 @@
 #include "k.h"
 #include "h.h"
 #include "w.h"
-#include "dwdx.h"
 
 namespace amici {
 namespace model_model_calvetti_py {
 
-void dydx_model_calvetti_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx){
+void dydx_model_calvetti_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w){
     dydx[0] = 1;
     dydx[3] = std::pow(L1, 3)*(2*f1/R1 - 2*(R3*f3 + f1*(R1 + R2) + f2*(R2 + R3))/std::pow(R1, 2) + 4/std::pow(R1, 2))/std::pow(V1, 3);
     dydx[7] = 1;
diff --git a/models/model_calvetti_py/model_calvetti_py.h b/models/model_calvetti_py/model_calvetti_py.h
index d18deb259f..834ebef1b7 100644
--- a/models/model_calvetti_py/model_calvetti_py.h
+++ b/models/model_calvetti_py/model_calvetti_py.h
@@ -57,7 +57,7 @@ extern void dxdotdw_rowvals_model_calvetti_py(SUNMatrixWrapper &rowvals);
 extern void dxdotdx_explicit_model_calvetti_py(realtype *dxdotdx_explicit, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *dx, const realtype *w);
 extern void dxdotdx_explicit_colptrs_model_calvetti_py(SUNMatrixWrapper &colptrs);
 extern void dxdotdx_explicit_rowvals_model_calvetti_py(SUNMatrixWrapper &rowvals);
-extern void dydx_model_calvetti_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx);
+extern void dydx_model_calvetti_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w);
 
 
 
@@ -309,8 +309,8 @@ class Model_model_calvetti_py : public amici::Model_DAE {
     }
 
 
-    void fdydx(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx) override {
-        dydx_model_calvetti_py(dydx, t, x, p, k, h, w, dwdx);
+    void fdydx(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w) override {
+        dydx_model_calvetti_py(dydx, t, x, p, k, h, w);
     }
 
 
diff --git a/models/model_dirac_py/dydx.cpp b/models/model_dirac_py/dydx.cpp
index 8c7f99fbb9..161f78c3e5 100644
--- a/models/model_dirac_py/dydx.cpp
+++ b/models/model_dirac_py/dydx.cpp
@@ -9,7 +9,7 @@
 namespace amici {
 namespace model_model_dirac_py {
 
-void dydx_model_dirac_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx){
+void dydx_model_dirac_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w){
     dydx[1] = 1;
 }
 
diff --git a/models/model_dirac_py/model_dirac_py.h b/models/model_dirac_py/model_dirac_py.h
index caef0fb751..5152cc2ff6 100644
--- a/models/model_dirac_py/model_dirac_py.h
+++ b/models/model_dirac_py/model_dirac_py.h
@@ -57,7 +57,7 @@ extern void dxdotdp_explicit_rowvals_model_dirac_py(SUNMatrixWrapper &rowvals);
 extern void dxdotdx_explicit_model_dirac_py(realtype *dxdotdx_explicit, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w);
 extern void dxdotdx_explicit_colptrs_model_dirac_py(SUNMatrixWrapper &colptrs);
 extern void dxdotdx_explicit_rowvals_model_dirac_py(SUNMatrixWrapper &rowvals);
-extern void dydx_model_dirac_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx);
+extern void dydx_model_dirac_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w);
 
 
 
@@ -300,8 +300,8 @@ class Model_model_dirac_py : public amici::Model_ODE {
     }
 
 
-    void fdydx(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx) override {
-        dydx_model_dirac_py(dydx, t, x, p, k, h, w, dwdx);
+    void fdydx(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w) override {
+        dydx_model_dirac_py(dydx, t, x, p, k, h, w);
     }
 
 
diff --git a/models/model_events_py/dydx.cpp b/models/model_events_py/dydx.cpp
index 6334475430..ee84fc2bac 100644
--- a/models/model_events_py/dydx.cpp
+++ b/models/model_events_py/dydx.cpp
@@ -10,7 +10,7 @@
 namespace amici {
 namespace model_model_events_py {
 
-void dydx_model_events_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx){
+void dydx_model_events_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w){
     dydx[0] = p4;
     dydx[1] = p4;
     dydx[2] = p4;
diff --git a/models/model_events_py/model_events_py.h b/models/model_events_py/model_events_py.h
index 1995371f93..5a03c91a22 100644
--- a/models/model_events_py/model_events_py.h
+++ b/models/model_events_py/model_events_py.h
@@ -57,7 +57,7 @@ extern void dxdotdp_explicit_rowvals_model_events_py(SUNMatrixWrapper &rowvals);
 extern void dxdotdx_explicit_model_events_py(realtype *dxdotdx_explicit, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w);
 extern void dxdotdx_explicit_colptrs_model_events_py(SUNMatrixWrapper &colptrs);
 extern void dxdotdx_explicit_rowvals_model_events_py(SUNMatrixWrapper &rowvals);
-extern void dydx_model_events_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx);
+extern void dydx_model_events_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w);
 extern void dydp_model_events_py(realtype *dydp, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const int ip, const realtype *w, const realtype *tcl, const realtype *dtcldp, const realtype *spl, const realtype *sspl);
 extern void dzdx_model_events_py(realtype *dzdx, const int ie, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h);
 
@@ -319,8 +319,8 @@ class Model_model_events_py : public amici::Model_ODE {
     }
 
 
-    void fdydx(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx) override {
-        dydx_model_events_py(dydx, t, x, p, k, h, w, dwdx);
+    void fdydx(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w) override {
+        dydx_model_events_py(dydx, t, x, p, k, h, w);
     }
 
 
diff --git a/models/model_jakstat_adjoint_py/dydx.cpp b/models/model_jakstat_adjoint_py/dydx.cpp
index c7038c3879..f58e5711b0 100644
--- a/models/model_jakstat_adjoint_py/dydx.cpp
+++ b/models/model_jakstat_adjoint_py/dydx.cpp
@@ -10,7 +10,7 @@
 namespace amici {
 namespace model_model_jakstat_adjoint_py {
 
-void dydx_model_jakstat_adjoint_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx){
+void dydx_model_jakstat_adjoint_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w){
     dydx[1] = scale_tSTAT/init_STAT;
     dydx[3] = scale_pSTAT/init_STAT;
     dydx[4] = scale_tSTAT/init_STAT;
diff --git a/models/model_jakstat_adjoint_py/model_jakstat_adjoint_py.h b/models/model_jakstat_adjoint_py/model_jakstat_adjoint_py.h
index 19454c9f24..8f9e90b82e 100644
--- a/models/model_jakstat_adjoint_py/model_jakstat_adjoint_py.h
+++ b/models/model_jakstat_adjoint_py/model_jakstat_adjoint_py.h
@@ -57,7 +57,7 @@ extern void dxdotdp_explicit_rowvals_model_jakstat_adjoint_py(SUNMatrixWrapper &
 extern void dxdotdx_explicit_model_jakstat_adjoint_py(realtype *dxdotdx_explicit, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w);
 extern void dxdotdx_explicit_colptrs_model_jakstat_adjoint_py(SUNMatrixWrapper &colptrs);
 extern void dxdotdx_explicit_rowvals_model_jakstat_adjoint_py(SUNMatrixWrapper &rowvals);
-extern void dydx_model_jakstat_adjoint_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx);
+extern void dydx_model_jakstat_adjoint_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w);
 extern void dydp_model_jakstat_adjoint_py(realtype *dydp, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const int ip, const realtype *w, const realtype *tcl, const realtype *dtcldp, const realtype *spl, const realtype *sspl);
 
 
@@ -308,8 +308,8 @@ class Model_model_jakstat_adjoint_py : public amici::Model_ODE {
     }
 
 
-    void fdydx(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx) override {
-        dydx_model_jakstat_adjoint_py(dydx, t, x, p, k, h, w, dwdx);
+    void fdydx(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w) override {
+        dydx_model_jakstat_adjoint_py(dydx, t, x, p, k, h, w);
     }
 
 
diff --git a/models/model_nested_events_py/dydx.cpp b/models/model_nested_events_py/dydx.cpp
index ac803f6931..f7f4c7f044 100644
--- a/models/model_nested_events_py/dydx.cpp
+++ b/models/model_nested_events_py/dydx.cpp
@@ -9,7 +9,7 @@
 namespace amici {
 namespace model_model_nested_events_py {
 
-void dydx_model_nested_events_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx){
+void dydx_model_nested_events_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w){
     dydx[0] = 1;
 }
 
diff --git a/models/model_nested_events_py/model_nested_events_py.h b/models/model_nested_events_py/model_nested_events_py.h
index 6925d8df34..1406e3da07 100644
--- a/models/model_nested_events_py/model_nested_events_py.h
+++ b/models/model_nested_events_py/model_nested_events_py.h
@@ -57,7 +57,7 @@ extern void dxdotdp_explicit_rowvals_model_nested_events_py(SUNMatrixWrapper &ro
 extern void dxdotdx_explicit_model_nested_events_py(realtype *dxdotdx_explicit, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w);
 extern void dxdotdx_explicit_colptrs_model_nested_events_py(SUNMatrixWrapper &colptrs);
 extern void dxdotdx_explicit_rowvals_model_nested_events_py(SUNMatrixWrapper &rowvals);
-extern void dydx_model_nested_events_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx);
+extern void dydx_model_nested_events_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w);
 
 
 
@@ -304,8 +304,8 @@ class Model_model_nested_events_py : public amici::Model_ODE {
     }
 
 
-    void fdydx(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx) override {
-        dydx_model_nested_events_py(dydx, t, x, p, k, h, w, dwdx);
+    void fdydx(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w) override {
+        dydx_model_nested_events_py(dydx, t, x, p, k, h, w);
     }
 
 
diff --git a/models/model_neuron_py/dydx.cpp b/models/model_neuron_py/dydx.cpp
index 5854c7726e..fe3c61f9f6 100644
--- a/models/model_neuron_py/dydx.cpp
+++ b/models/model_neuron_py/dydx.cpp
@@ -10,7 +10,7 @@
 namespace amici {
 namespace model_model_neuron_py {
 
-void dydx_model_neuron_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx){
+void dydx_model_neuron_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w){
     dydx[0] = 1;
 }
 
diff --git a/models/model_neuron_py/model_neuron_py.h b/models/model_neuron_py/model_neuron_py.h
index 4d35a8a443..9c90582736 100644
--- a/models/model_neuron_py/model_neuron_py.h
+++ b/models/model_neuron_py/model_neuron_py.h
@@ -57,7 +57,7 @@ extern void dxdotdp_explicit_rowvals_model_neuron_py(SUNMatrixWrapper &rowvals);
 extern void dxdotdx_explicit_model_neuron_py(realtype *dxdotdx_explicit, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w);
 extern void dxdotdx_explicit_colptrs_model_neuron_py(SUNMatrixWrapper &colptrs);
 extern void dxdotdx_explicit_rowvals_model_neuron_py(SUNMatrixWrapper &rowvals);
-extern void dydx_model_neuron_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx);
+extern void dydx_model_neuron_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w);
 
 extern void dzdx_model_neuron_py(realtype *dzdx, const int ie, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h);
 
@@ -316,8 +316,8 @@ class Model_model_neuron_py : public amici::Model_ODE {
     }
 
 
-    void fdydx(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx) override {
-        dydx_model_neuron_py(dydx, t, x, p, k, h, w, dwdx);
+    void fdydx(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w) override {
+        dydx_model_neuron_py(dydx, t, x, p, k, h, w);
     }
 
 
diff --git a/models/model_robertson_py/dydx.cpp b/models/model_robertson_py/dydx.cpp
index 3fdd467ad8..50f1b062c9 100644
--- a/models/model_robertson_py/dydx.cpp
+++ b/models/model_robertson_py/dydx.cpp
@@ -9,7 +9,7 @@
 namespace amici {
 namespace model_model_robertson_py {
 
-void dydx_model_robertson_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx){
+void dydx_model_robertson_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w){
     dydx[0] = 1;
     dydx[4] = 10000.0;
     dydx[8] = 1;
diff --git a/models/model_robertson_py/model_robertson_py.h b/models/model_robertson_py/model_robertson_py.h
index 591f64acf9..6e91cfd829 100644
--- a/models/model_robertson_py/model_robertson_py.h
+++ b/models/model_robertson_py/model_robertson_py.h
@@ -57,7 +57,7 @@ extern void dxdotdp_explicit_rowvals_model_robertson_py(SUNMatrixWrapper &rowval
 extern void dxdotdx_explicit_model_robertson_py(realtype *dxdotdx_explicit, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *dx, const realtype *w);
 extern void dxdotdx_explicit_colptrs_model_robertson_py(SUNMatrixWrapper &colptrs);
 extern void dxdotdx_explicit_rowvals_model_robertson_py(SUNMatrixWrapper &rowvals);
-extern void dydx_model_robertson_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx);
+extern void dydx_model_robertson_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w);
 
 
 
@@ -292,8 +292,8 @@ class Model_model_robertson_py : public amici::Model_DAE {
     }
 
 
-    void fdydx(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx) override {
-        dydx_model_robertson_py(dydx, t, x, p, k, h, w, dwdx);
+    void fdydx(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w) override {
+        dydx_model_robertson_py(dydx, t, x, p, k, h, w);
     }
 
 
diff --git a/models/model_steadystate_py/dydx.cpp b/models/model_steadystate_py/dydx.cpp
index 91b5853abe..554039f1f2 100644
--- a/models/model_steadystate_py/dydx.cpp
+++ b/models/model_steadystate_py/dydx.cpp
@@ -9,7 +9,7 @@
 namespace amici {
 namespace model_model_steadystate_py {
 
-void dydx_model_steadystate_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx){
+void dydx_model_steadystate_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w){
     dydx[0] = 1;
     dydx[4] = 1;
     dydx[8] = 1;
diff --git a/models/model_steadystate_py/model_steadystate_py.h b/models/model_steadystate_py/model_steadystate_py.h
index 3e2429a109..1e6243b822 100644
--- a/models/model_steadystate_py/model_steadystate_py.h
+++ b/models/model_steadystate_py/model_steadystate_py.h
@@ -57,7 +57,7 @@ extern void dxdotdp_explicit_rowvals_model_steadystate_py(SUNMatrixWrapper &rowv
 extern void dxdotdx_explicit_model_steadystate_py(realtype *dxdotdx_explicit, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w);
 extern void dxdotdx_explicit_colptrs_model_steadystate_py(SUNMatrixWrapper &colptrs);
 extern void dxdotdx_explicit_rowvals_model_steadystate_py(SUNMatrixWrapper &rowvals);
-extern void dydx_model_steadystate_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx);
+extern void dydx_model_steadystate_py(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w);
 
 
 
@@ -292,8 +292,8 @@ class Model_model_steadystate_py : public amici::Model_ODE {
     }
 
 
-    void fdydx(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w, const realtype *dwdx) override {
-        dydx_model_steadystate_py(dydx, t, x, p, k, h, w, dwdx);
+    void fdydx(realtype *dydx, const realtype t, const realtype *x, const realtype *p, const realtype *k, const realtype *h, const realtype *w) override {
+        dydx_model_steadystate_py(dydx, t, x, p, k, h, w);
     }
 
 
diff --git a/python/sdist/amici/_codegen/cxx_functions.py b/python/sdist/amici/_codegen/cxx_functions.py
index 574093e60a..5151df84a4 100644
--- a/python/sdist/amici/_codegen/cxx_functions.py
+++ b/python/sdist/amici/_codegen/cxx_functions.py
@@ -78,7 +78,8 @@ def get_deps(self, ode: bool) -> list[str]:
         )
 
     def var_in_signature(self, varname: str, ode: bool = True) -> bool:
-        """Check if a variable is in the function signature.
+        """
+        Check if a variable is in the function signature as input (``const``).
 
         :param varname: name of the variable to check
         :param ode: whether to check the ODE (``True``) or DAE (``False``)
@@ -225,7 +226,7 @@ def var_in_signature(self, varname: str, ode: bool = True) -> bool:
     "dydx": _FunctionInfo(
         "realtype *dydx, const realtype t, const realtype *x, "
         "const realtype *p, const realtype *k, const realtype *h, "
-        "const realtype *w, const realtype *dwdx",
+        "const realtype *w"
     ),
     "dydp": _FunctionInfo(
         "realtype *dydp, const realtype t, const realtype *x, "
@@ -483,6 +484,6 @@ def var_in_function_signature(name: str, varname: str, ode: bool) -> bool:
 
     :return:
         boolean indicating whether the variable occurs in the function
-        signature
+        signature as ``const`` input.
     """
     return name in functions and functions[name].var_in_signature(varname, ode)
diff --git a/python/sdist/amici/de_model.py b/python/sdist/amici/de_model.py
index 9666847204..f722558945 100644
--- a/python/sdist/amici/de_model.py
+++ b/python/sdist/amici/de_model.py
@@ -2147,16 +2147,15 @@ def sym_or_eq(self, name: str, varname: str) -> sp.Matrix:
             the variable symbols if the variable is part of the signature and
             the variable equations otherwise.
         """
-        # dwdx and dwdp will be dynamically computed and their ordering
-        # within a column may differ from the initialization of symbols here,
-        # so those are not safe to use. Not removing them from signature as
-        # this would break backwards compatibility.
-        if var_in_function_signature(
-            name, varname, self.is_ode()
-        ) and varname not in [
-            "dwdx",
-            "dwdp",
-        ]:
+        if var_in_function_signature(name, varname, self.is_ode()):
+            if varname in [
+                "dwdx",
+                "dwdp",
+            ]:
+                # dwdx and dwdp will be dynamically computed, and their
+                #  ordering within a column may differ from the initialization
+                #  of symbols here, so those are not safe to use.
+                raise AssertionError()
             return self.sym(varname)
         else:
             return self.eq(varname)
diff --git a/src/abstract_model.cpp b/src/abstract_model.cpp
index 351314967c..3c8ba018b6 100644
--- a/src/abstract_model.cpp
+++ b/src/abstract_model.cpp
@@ -97,7 +97,7 @@ void AbstractModel::fdydp(
 void AbstractModel::fdydx(
     realtype* /*dydx*/, realtype const /*t*/, realtype const* /*x*/,
     realtype const* /*p*/, realtype const* /*k*/, realtype const* /*h*/,
-    realtype const* /*w*/, realtype const* /*dwdx*/
+    realtype const* /*w*/
 ) {
     throw AmiException(
         "Requested functionality is not supported as %s is "
diff --git a/src/model.cpp b/src/model.cpp
index 3c16109e0b..4cac939f6e 100644
--- a/src/model.cpp
+++ b/src/model.cpp
@@ -2084,11 +2084,10 @@ void Model::fdydx(realtype const t, AmiVector const& x) {
     derived_state_.dydx_.assign(ny * nx_solver, 0.0);
 
     fw(t, x_pos, false);
-    fdwdx(t, x_pos, false);
     fdydx(
         derived_state_.dydx_.data(), t, x_pos, state_.unscaledParameters.data(),
         state_.fixedParameters.data(), state_.h.data(),
-        derived_state_.w_.data(), derived_state_.dwdx_.data()
+        derived_state_.w_.data()
     );
 
     if (always_check_finite_) {