diff --git a/pywrapper/pyecx/py_common.c b/pywrapper/pyecx/py_common.c
index bb4eade..829c218 100644
--- a/pywrapper/pyecx/py_common.c
+++ b/pywrapper/pyecx/py_common.c
@@ -1,5 +1,6 @@
-#include "py_common.h" 
-
+#define PY_SSIZE_T_CLEAN
+#include <Python.h>
+#include "py_common.h"
 
 Py_buffer create_new_buffer(char *format, Py_ssize_t itemsize, Py_ssize_t ndim, Py_ssize_t *shape){
 
diff --git a/pywrapper/pyecx/py_common.h b/pywrapper/pyecx/py_common.h
index 8520919..c2f1c2a 100644
--- a/pywrapper/pyecx/py_common.h
+++ b/pywrapper/pyecx/py_common.h
@@ -1,8 +1,5 @@
 #ifndef PY_COMMON_H
 #define PY_COMMON_H
-#define PY_SSIZE_T_CLEAN
-#include <Python.h>
-#include "ecx.h"
 Py_buffer create_new_buffer(char *format, Py_ssize_t itemsize, Py_ssize_t ndim, Py_ssize_t *shape);
 Py_buffer *get_buffer(PyObject *o);
 #endif
\ No newline at end of file
diff --git a/pywrapper/pyecx/py_core.c b/pywrapper/pyecx/py_core.c
index eaaf3f2..6585858 100644
--- a/pywrapper/pyecx/py_core.c
+++ b/pywrapper/pyecx/py_core.c
@@ -1,3 +1,6 @@
+#define PY_SSIZE_T_CLEAN
+#include <Python.h>
+#include "ecx.h"
 #include "py_common.h"
 
 PyDoc_STRVAR(module_docstring, "C extension wrapping the CORE module of the Fortran ecx library.");
diff --git a/pywrapper/pyecx/py_eis.c b/pywrapper/pyecx/py_eis.c
index 4eeabaa..88cc884 100644
--- a/pywrapper/pyecx/py_eis.c
+++ b/pywrapper/pyecx/py_eis.c
@@ -1,3 +1,6 @@
+#define PY_SSIZE_T_CLEAN
+#include <Python.h>
+#include "ecx.h"
 #include "py_common.h"
 
 PyDoc_STRVAR(module_docstring, "C extension wrapping the EIS module of the Fortran ecx library.");
diff --git a/pywrapper/pyecx/py_kinetics.c b/pywrapper/pyecx/py_kinetics.c
index bc233d2..31f53ca 100644
--- a/pywrapper/pyecx/py_kinetics.c
+++ b/pywrapper/pyecx/py_kinetics.c
@@ -1,3 +1,6 @@
+#define PY_SSIZE_T_CLEAN
+#include <Python.h>
+#include "ecx.h"
 #include "py_common.h"
 
 const char ERR_MSG_ARGS[] = "U must be objects with the buffer protocol and all other parameter are floats.";