diff --git a/include/ip.h b/include/ip.h
index ef3d903..64bc8ee 100644
--- a/include/ip.h
+++ b/include/ip.h
@@ -260,8 +260,8 @@ namespace Tins {
          * \return The total length of this IP PDU.
          */
         uint16_t tot_len() const { 
-            // BSD wants this in host byte order............
-            #ifdef BSD
+            // FreeBSD wants this in host byte order............
+            #ifdef __FreeBSD__
             return _ip.tot_len; 
             #else
             return Endian::be_to_host(_ip.tot_len); 
diff --git a/src/ip.cpp b/src/ip.cpp
index f7590eb..c95a2be 100644
--- a/src/ip.cpp
+++ b/src/ip.cpp
@@ -170,8 +170,8 @@ void IP::tos(uint8_t new_tos) {
 }
 
 void IP::tot_len(uint16_t new_tot_len) {
-    // BSD wants this in host byte order............
-    #ifdef BSD
+    // FreeBSD wants this in host byte order............
+    #ifdef __FreeBSD__
     _ip.tot_len = new_tot_len;
     #else
     _ip.tot_len = Endian::host_to_be(new_tot_len);