diff --git a/CHANGELOG b/CHANGELOG
index d92f8fa92..dea75d81b 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,9 @@
 # Nmap Changelog ($Id$); -*-text-*-
 
+o [Ncat] Applied a blocking-socket workaround for a bug that could
+  prevent some sends from working in listen mode. The problem was
+  reported by Jonas Wielicki. [Alex Weber, David Fifield]
+
 o Protocol scan (-sO) probes for TCP, UDP, and SCTP now go to ports
   80, 40125, and 80 respectively, instead of being randomly generated
   or going to the same port as the source port. [David Fifield]
diff --git a/ncat/ncat_core.c b/ncat/ncat_core.c
index 8e0b55735..7a7407aae 100644
--- a/ncat/ncat_core.c
+++ b/ncat/ncat_core.c
@@ -291,6 +291,22 @@ int fdinfo_send(struct fdinfo *fdn, const char *buf, size_t size)
     return send(fdn->fd, buf, size, 0);
 }
 
+/* If we are sending a large amount of data, we might momentarily run out of send
+   space and get an EAGAIN when we send. Temporarily convert a socket to
+   blocking more, do the send, and unblock it again. Assumes that the socket was
+   in nonblocking mode to begin with; it has the side effect of leaving the
+   socket nonblocking on return. */
+static int blocking_fdinfo_send(struct fdinfo *fdn, const char *buf, size_t size)
+{
+    int ret;
+
+    block_socket(fdn->fd);
+    ret = fdinfo_send(fdn, buf, size);
+    unblock_socket(fdn->fd);
+
+    return ret;
+}
+
 int ncat_send(struct fdinfo *fdn, const char *buf, size_t size)
 {
     int n;
@@ -298,7 +314,7 @@ int ncat_send(struct fdinfo *fdn, const char *buf, size_t size)
     if (o.recvonly)
         return size;
 
-    n = fdinfo_send(fdn, buf, size);
+    n = blocking_fdinfo_send(fdn, buf, size);
     if (n <= 0)
         return n;
 
@@ -323,7 +339,7 @@ int ncat_broadcast(fd_set *fds, const fd_list_t *fdlist, const char *msg, size_t
             continue;
 
         fdn = get_fdinfo(fdlist, i);
-        if (fdinfo_send(fdn, msg, size) <= 0) {
+        if (blocking_fdinfo_send(fdn, msg, size) <= 0) {
             if (o.debug > 1)
                 logdebug("Error sending to fd %d: %s.\n", i, socket_strerror(socket_errno()));
             ret = -1;