diff --git a/python/aubio/aubio_wrap.c b/python/aubio/aubio_wrap.c
index 3a2380e..060b8af 100644
--- a/python/aubio/aubio_wrap.c
+++ b/python/aubio/aubio_wrap.c
@@ -844,7 +844,7 @@ SWIG_Python_AddErrorMsg(const char* mesg)
Py_DECREF(old_str);
Py_DECREF(value);
} else {
- PyErr_Format(PyExc_RuntimeError, mesg);
+ PyErr_Format(PyExc_RuntimeError, "%s", mesg);
}
}