diff --git a/equilibrate/cython/CMakeLists.txt b/equilibrate/cython/CMakeLists.txt
index 95b0e61..29e682e 100644
--- a/equilibrate/cython/CMakeLists.txt
+++ b/equilibrate/cython/CMakeLists.txt
@@ -10,5 +10,5 @@ add_library(_equilibrate MODULE ${_equilibrate})
 python_extension_module(_equilibrate)
 
 target_link_libraries(_equilibrate equilibrate_c_api)
-target_include_directories(_equilibrate PUBLIC ${NumPy_INCLUDE_DIRS})
+target_include_directories(_equilibrate PUBLIC ${NumPy_INCLUDE_DIRS} ${CMAKE_CURRENT_SOURCE_DIR})
 set_property(TARGET _equilibrate PROPERTY LINKER_LANGUAGE Fortran)
\ No newline at end of file
diff --git a/equilibrate/cython/ChemEquiAnalysis_pxd.pxd b/equilibrate/cython/ChemEquiAnalysis_pxd.pxd
index e1b40d1..3a930eb 100644
--- a/equilibrate/cython/ChemEquiAnalysis_pxd.pxd
+++ b/equilibrate/cython/ChemEquiAnalysis_pxd.pxd
@@ -2,58 +2,62 @@ from libcpp cimport bool as cbool
 cdef extern from "<stdbool.h>":
   pass
 
+cdef extern from "_equilibrate.h":
+  struct ChemEquiAnalysis:
+    pass
+
 # Allocate and destroy
-cdef extern void *allocate_chemequianalysis();
-cdef extern void deallocate_chemequianalysis(void *ptr);
+cdef extern ChemEquiAnalysis *allocate_chemequianalysis();
+cdef extern void deallocate_chemequianalysis(ChemEquiAnalysis *ptr);
 
 # Wrappers for functions
 
-cdef extern void chemequianalysis_create_wrapper(void *ptr, char *thermofile, 
+cdef extern void chemequianalysis_create_wrapper(ChemEquiAnalysis *ptr, char *thermofile, 
                          cbool *atoms_present, int *atoms_dim, char *atoms,
                          cbool *species_present, int *species_dim, char *species,
                          char *err);
-cdef extern void chemequianalysis_solve_wrapper(void *ptr, double *P, double *T,
+cdef extern void chemequianalysis_solve_wrapper(ChemEquiAnalysis *ptr, double *P, double *T,
                          cbool *molfracs_atoms_present, int *molfracs_atoms_dim, double *molfracs_atoms, 
                          cbool *molfracs_species_present, int *molfracs_species_dim, double *molfracs_species, 
                          cbool *converged, char *err)
 
 # Getters and setters
 
-cdef extern void chemequianalysis_atoms_names_get_size(void *ptr, int *dim1)
-cdef extern void chemequianalysis_atoms_names_get(void *ptr, int *dim1, char* arr)
+cdef extern void chemequianalysis_atoms_names_get_size(ChemEquiAnalysis *ptr, int *dim1)
+cdef extern void chemequianalysis_atoms_names_get(ChemEquiAnalysis *ptr, int *dim1, char* arr)
 
-cdef extern void chemequianalysis_species_names_get_size(void *ptr, int *dim1)
-cdef extern void chemequianalysis_species_names_get(void *ptr, int *dim1, char* arr)
+cdef extern void chemequianalysis_species_names_get_size(ChemEquiAnalysis *ptr, int *dim1)
+cdef extern void chemequianalysis_species_names_get(ChemEquiAnalysis *ptr, int *dim1, char* arr)
 
-cdef extern void chemequianalysis_gas_names_get_size(void *ptr, int *dim1)
-cdef extern void chemequianalysis_gas_names_get(void *ptr, int *dim1, char* arr)
+cdef extern void chemequianalysis_gas_names_get_size(ChemEquiAnalysis *ptr, int *dim1)
+cdef extern void chemequianalysis_gas_names_get(ChemEquiAnalysis *ptr, int *dim1, char* arr)
 
-cdef extern void chemequianalysis_condensate_names_get_size(void *ptr, int *dim1)
-cdef extern void chemequianalysis_condensate_names_get(void *ptr, int *dim1, char* arr)
+cdef extern void chemequianalysis_condensate_names_get_size(ChemEquiAnalysis *ptr, int *dim1)
+cdef extern void chemequianalysis_condensate_names_get(ChemEquiAnalysis *ptr, int *dim1, char* arr)
 
-cdef extern void chemequianalysis_molfracs_atoms_get_size(void *ptr, int *dim1)
-cdef extern void chemequianalysis_molfracs_atoms_get(void *ptr, int *dim1, double *arr)
+cdef extern void chemequianalysis_molfracs_atoms_get_size(ChemEquiAnalysis *ptr, int *dim1)
+cdef extern void chemequianalysis_molfracs_atoms_get(ChemEquiAnalysis *ptr, int *dim1, double *arr)
 
-cdef extern void chemequianalysis_molfracs_species_get_size(void *ptr, int *dim1)
-cdef extern void chemequianalysis_molfracs_species_get(void *ptr, int *dim1, double *arr)
+cdef extern void chemequianalysis_molfracs_species_get_size(ChemEquiAnalysis *ptr, int *dim1)
+cdef extern void chemequianalysis_molfracs_species_get(ChemEquiAnalysis *ptr, int *dim1, double *arr)
 
-cdef extern void chemequianalysis_massfracs_species_get_size(void *ptr, int *dim1)
-cdef extern void chemequianalysis_massfracs_species_get(void *ptr, int *dim1, double *arr)
+cdef extern void chemequianalysis_massfracs_species_get_size(ChemEquiAnalysis *ptr, int *dim1)
+cdef extern void chemequianalysis_massfracs_species_get(ChemEquiAnalysis *ptr, int *dim1, double *arr)
 
-cdef extern void chemequianalysis_molfracs_atoms_gas_get_size(void *ptr, int *dim1)
-cdef extern void chemequianalysis_molfracs_atoms_gas_get(void *ptr, int *dim1, double *arr)
+cdef extern void chemequianalysis_molfracs_atoms_gas_get_size(ChemEquiAnalysis *ptr, int *dim1)
+cdef extern void chemequianalysis_molfracs_atoms_gas_get(ChemEquiAnalysis *ptr, int *dim1, double *arr)
 
-cdef extern void chemequianalysis_molfracs_species_gas_get_size(void *ptr, int *dim1)
-cdef extern void chemequianalysis_molfracs_species_gas_get(void *ptr, int *dim1, double *arr)
+cdef extern void chemequianalysis_molfracs_species_gas_get_size(ChemEquiAnalysis *ptr, int *dim1)
+cdef extern void chemequianalysis_molfracs_species_gas_get(ChemEquiAnalysis *ptr, int *dim1, double *arr)
 
-cdef extern void chemequianalysis_molfracs_atoms_condensate_get_size(void *ptr, int *dim1)
-cdef extern void chemequianalysis_molfracs_atoms_condensate_get(void *ptr, int *dim1, double *arr)
+cdef extern void chemequianalysis_molfracs_atoms_condensate_get_size(ChemEquiAnalysis *ptr, int *dim1)
+cdef extern void chemequianalysis_molfracs_atoms_condensate_get(ChemEquiAnalysis *ptr, int *dim1, double *arr)
 
-cdef extern void chemequianalysis_molfracs_species_condensate_get_size(void *ptr, int *dim1)
-cdef extern void chemequianalysis_molfracs_species_condensate_get(void *ptr, int *dim1, double *arr)
+cdef extern void chemequianalysis_molfracs_species_condensate_get_size(ChemEquiAnalysis *ptr, int *dim1)
+cdef extern void chemequianalysis_molfracs_species_condensate_get(ChemEquiAnalysis *ptr, int *dim1, double *arr)
 
-cdef extern void chemequianalysis_verbose_get(void *ptr, cbool *val)
-cdef extern void chemequianalysis_verbose_set(void *ptr, cbool *val)
+cdef extern void chemequianalysis_verbose_get(ChemEquiAnalysis *ptr, cbool *val)
+cdef extern void chemequianalysis_verbose_set(ChemEquiAnalysis *ptr, cbool *val)
 
-cdef extern void chemequianalysis_mass_tol_get(void *ptr, double *val)
-cdef extern void chemequianalysis_mass_tol_set(void *ptr, double *val)
\ No newline at end of file
+cdef extern void chemequianalysis_mass_tol_get(ChemEquiAnalysis *ptr, double *val)
+cdef extern void chemequianalysis_mass_tol_set(ChemEquiAnalysis *ptr, double *val)
\ No newline at end of file
diff --git a/equilibrate/cython/_equilibrate.h b/equilibrate/cython/_equilibrate.h
new file mode 100644
index 0000000..740a3ef
--- /dev/null
+++ b/equilibrate/cython/_equilibrate.h
@@ -0,0 +1 @@
+struct ChemEquiAnalysis{};
\ No newline at end of file
diff --git a/equilibrate/cython/_equilibrate.pyx b/equilibrate/cython/_equilibrate.pyx
index 31a4059..e501520 100644
--- a/equilibrate/cython/_equilibrate.pyx
+++ b/equilibrate/cython/_equilibrate.pyx
@@ -12,7 +12,7 @@ DEF ERR_LEN = 1024;
 
 cdef class ChemEquiAnalysis:
 
-  cdef void *_ptr
+  cdef cea_pxd.ChemEquiAnalysis *_ptr
   cdef cbool _init_called
 
   def __cinit__(self, thermofile = None, atoms = None, species = None):