diff --git a/CHANGELOG b/CHANGELOG
index 782f4587b..9173e0593 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,8 @@
 #Nmap Changelog ($Id$); -*-text-*-
 
+o [GH#2732] Fix a potential crash on 32-bit platforms in debug mode due to
+  incorrect format specifier for 64-bit integer type. [Christopher Chavez]
+
 o [GH#3201][GH#3367] Increase line length limit for nmap-service-probes and
   correctly handle lines that are too long. [@liquidpele, Ashutosh Kumar Singh]
 
diff --git a/MACLookup.cc b/MACLookup.cc
index e3cfa6508..94b7d1de2 100644
--- a/MACLookup.cc
+++ b/MACLookup.cc
@@ -159,7 +159,7 @@ static void mac_prefix_init() {
     std::pair<MacMap::iterator, bool> status = MacTable.insert(std::pair<u64, const char *>(pfx, string_pool_substr(vendor, endptr)));
 
     if (!status.second && o.debugging > 1)
-      error("MAC prefix %0*lX is duplicated in %s; ignoring duplicates.", (int)(pfx >> 36), pfx & 0xfffffffffL, filename);
+      error("MAC prefix %0*" PRIX64 " is duplicated in %s; ignoring duplicates.", (int)(pfx >> 36), pfx & 0xfffffffffL, filename);
   }
 
   fclose(fp);