--- a/src/dnsbl.cpp	Thu Mar 30 10:31:23 2017 -0700
+++ b/src/dnsbl.cpp	Sun Apr 16 09:06:52 2017 -0700
@@ -316,9 +316,15 @@
     // process, which does the actual dns resolution.
     if (priv.err) return 0; // cannot ask more questions on this socket.
     if (maybe_ip && (qtype == ns_t_a)) {
-        // might be a bare ip address, try this first to avoid dns lookups that may not be needed
+        int c = 0;
+        const char q = question;
+        while (*q) {
+            if (*q == '.') c++;
+            q++;
+        }
+        // might be a bare IPv4 address, try this first to avoid dns lookups that may not be needed
         in_addr ip;
-        if (inet_aton(question, &ip)) {
+        if ((c == 3) && inet_aton(question, &ip)) {
             return ip.s_addr;
         }
     }