diff --git a/pythonmod/interface.i b/pythonmod/interface.i
index 473135f42..b5b0c5b67 100644
--- a/pythonmod/interface.i
+++ b/pythonmod/interface.i
@@ -53,7 +53,7 @@
      i = 0; cnt = 0;
      while (i < len) {
         char buf[LDNS_MAX_LABELLEN+1];
-        if(((unsigned int)name[i])+1 <= (int)sizeof(buf)) {
+        if(((unsigned int)name[i])+1 <= (unsigned int)sizeof(buf)) {
                 memmove(buf, name + i + 1, (unsigned int)name[i]);
                 buf[(unsigned int)name[i]] = 0;
                 PyList_SetItem(list, cnt, PyString_FromString(buf));