diff --git a/nmap_dns.cc b/nmap_dns.cc
index 5dc04007c..d8b8a0690 100644
--- a/nmap_dns.cc
+++ b/nmap_dns.cc
@@ -749,7 +749,7 @@ static void read_evt_handler(nsock_pool nsp, nsock_event evt, void *) {
       it != p.answers.end(); ++it )
   {
     const DNS::Answer &a = *it;
-    if(a.record_class == DNS::IN)
+    if(a.record_class == DNS::CLASS_IN)
     {
       switch(a.record_type)
       {
@@ -1416,7 +1416,7 @@ size_t DNS::Factory::buildSimpleRequest(const std::string &name, RECORD_TYPE rt,
   DNS_CHECK_ACCUMLATE(ret, tmp, putUnsignedShort(0, buf, ARCOUNT, maxlen));
   DNS_CHECK_ACCUMLATE(ret, tmp, putDomainName(name, buf, DATA, maxlen));
   DNS_CHECK_ACCUMLATE(ret, tmp, putUnsignedShort(rt, buf, ret, maxlen));
-  DNS_CHECK_ACCUMLATE(ret, tmp, putUnsignedShort(IN, buf, ret, maxlen));
+  DNS_CHECK_ACCUMLATE(ret, tmp, putUnsignedShort(CLASS_IN, buf, ret, maxlen));
 
   return ret;
 }
diff --git a/nmap_dns.h b/nmap_dns.h
index 7da8f0be8..9947a438c 100644
--- a/nmap_dns.h
+++ b/nmap_dns.h
@@ -189,7 +189,7 @@ typedef enum {
 } RECORD_TYPE;
 
 typedef enum {
-  IN = 1
+  CLASS_IN = 1
 } RECORD_CLASS;
 
 const u8 COMPRESSED_NAME = 0xc0;