diff --git a/src/_wrappers.c b/src/_wrappers.c
index 20e2459..2fdaed9 100644
--- a/src/_wrappers.c
+++ b/src/_wrappers.c
@@ -304,7 +304,7 @@ static PyObject *WraptWrapperBase_getattro(
 static int WraptWrapperBase_setattro(
         WraptWrapperBaseObject *self, PyObject *name, PyObject *value)
 {
-    static PyObject *self_prefix = NULL;
+    PyObject *self_prefix = NULL;
 
     PyObject *match = NULL;
 
@@ -313,16 +313,16 @@ static int WraptWrapperBase_setattro(
       return -1;
     }
 
-    if (!self_prefix) {
 #if PY_MAJOR_VERSION >= 3
-        self_prefix = PyUnicode_FromString("_self_");
+    self_prefix = PyUnicode_FromString("_self_");
 #else
-        self_prefix = PyString_FromString("_self_");
+    self_prefix = PyString_FromString("_self_");
 #endif
-    }
 
     match = PyEval_CallMethod(name, "startswith", "(O)", self_prefix);
 
+    Py_DECREF(self_prefix);
+
     if (match == Py_True) {
         Py_DECREF(match);