diff --git a/Include/sysmodule.h b/Include/sysmodule.h
index 3ff01bd..8ea7eb1 100644
--- a/Include/sysmodule.h
+++ b/Include/sysmodule.h
@@ -7,10 +7,10 @@
 extern "C" {
 #endif
 
-PyAPI_FUNC(PyObject *) PySys_GetObject(char *);
-PyAPI_FUNC(int) PySys_SetObject(char *, PyObject *);
+PyAPI_FUNC(PyObject *) PySys_GetObject(const char *);
+PyAPI_FUNC(int) PySys_SetObject(const char *, PyObject *);
 PyAPI_FUNC(void) PySys_SetArgv(int, char **);
-PyAPI_FUNC(void) PySys_SetPath(char *);
+PyAPI_FUNC(void) PySys_SetPath(const char *);
 
 PyAPI_FUNC(void) PySys_WriteStdout(const char *format, ...)
 			Py_GCC_ATTRIBUTE((format(printf, 1, 2)));
@@ -21,7 +21,7 @@
 PyAPI_DATA(int) _PySys_CheckInterval;
 
 PyAPI_FUNC(void) PySys_ResetWarnOptions(void);
-PyAPI_FUNC(void) PySys_AddWarnOption(char *);
+PyAPI_FUNC(void) PySys_AddWarnOption(const char *);
 
 #ifdef __cplusplus
 }
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 7b32f60..4f9313a 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -46,7 +46,7 @@
 #endif
 
 PyObject *
-PySys_GetObject(char *name)
+PySys_GetObject(const char *name)
 {
 	PyThreadState *tstate = PyThreadState_GET();
 	PyObject *sd = tstate->interp->sysdict;
@@ -56,7 +56,7 @@
 }
 
 int
-PySys_SetObject(char *name, PyObject *v)
+PySys_SetObject(const char *name, PyObject *v)
 {
 	PyThreadState *tstate = PyThreadState_GET();
 	PyObject *sd = tstate->interp->sysdict;
@@ -819,7 +819,7 @@
 }
 
 void
-PySys_AddWarnOption(char *s)
+PySys_AddWarnOption(const char *s)
 {
 	PyObject *str;
 
@@ -1128,10 +1128,10 @@
 }
 
 static PyObject *
-makepathobject(char *path, int delim)
+makepathobject(const char *path, int delim)
 {
 	int i, n;
-	char *p;
+	const char *p;
 	PyObject *v, *w;
 
 	n = 1;
@@ -1161,7 +1161,7 @@
 }
 
 void
-PySys_SetPath(char *path)
+PySys_SetPath(const char *path)
 {
 	PyObject *v;
 	if ((v = makepathobject(path, DELIM)) == NULL)