diff --git a/src/if_py_both.h b/src/if_py_both.h
index a8188c1..5a49d1e 100644
--- a/src/if_py_both.h
+++ b/src/if_py_both.h
@@ -3005,11 +3005,14 @@
     else
     {
 	char_u		*val;
-	PyObject	*todecref;
+	PyObject	*todecref2;
 
-	if ((val = StringToChars(valObject, &todecref)))
+	if ((val = StringToChars(valObject, &todecref2)))
+	{
 	    ret = set_option_value_for(key, 0, val, opt_flags,
 				    self->opt_type, self->from);
+	    Py_XDECREF(todecref2);
+	}
 	else
 	    ret = -1;
     }