diff --git a/extras/libmemif/examples/icmp_responder-eb/main.c b/extras/libmemif/examples/icmp_responder-eb/main.c
index 646a6ca..0e8b8f3 100644
--- a/extras/libmemif/examples/icmp_responder-eb/main.c
+++ b/extras/libmemif/examples/icmp_responder-eb/main.c
@@ -375,7 +375,7 @@
 }
 
 int
-control_fd_update (int fd, uint8_t events)
+control_fd_update (int fd, uint8_t events, void *ctx)
 {
   /* convert memif event definitions to epoll events */
   if (events & MEMIF_FD_EVENT_DEL)
@@ -562,7 +562,7 @@
   if (err != MEMIF_ERR_SUCCESS)
     INFO ("memif_buffer_free: %s", memif_strerror (err));
   c->rx_buf_num -= rx;
-  DBG ("freed %d buffers. %u/%u alloc/free buffers", fb, c->rx_buf_num,
+  DBG ("freed %d buffers. %u/%u alloc/free buffers", rx, c->rx_buf_num,
        MAX_MEMIF_BUFS - c->rx_buf_num);
   return 0;
 }
@@ -637,7 +637,7 @@
     INFO ("memif_buffer_free: %s", memif_strerror (err));
   c->rx_buf_num -= rx;
   DBG ("freed %d buffers. %u/%u alloc/free buffers",
-       fb, c->rx_buf_num, MAX_MEMIF_BUFS - c->rx_buf_num);
+       rx, c->rx_buf_num, MAX_MEMIF_BUFS - c->rx_buf_num);
   return 0;
 }
 
diff --git a/extras/libmemif/examples/icmp_responder-epoll/main.c b/extras/libmemif/examples/icmp_responder-epoll/main.c
index ecc05a4..0e9d96e 100644
--- a/extras/libmemif/examples/icmp_responder-epoll/main.c
+++ b/extras/libmemif/examples/icmp_responder-epoll/main.c
@@ -304,7 +304,7 @@
 /* user needs to watch new fd or stop watching fd that is about to be closed.
     control fd will be modified during connection establishment to minimize CPU usage */
 int
-control_fd_update (int fd, uint8_t events)
+control_fd_update (int fd, uint8_t events, void *ctx)
 {
   /* convert memif event definitions to epoll events */
   if (events & MEMIF_FD_EVENT_DEL)
@@ -436,7 +436,7 @@
     INFO ("memif_buffer_free: %s", memif_strerror (err));
   c->rx_buf_num -= rx;
   DBG ("freed %d buffers. %u/%u alloc/free buffers",
-       fb, c->rx_buf_num, MAX_MEMIF_BUFS - c->rx_buf_num);
+       rx, c->rx_buf_num, MAX_MEMIF_BUFS - c->rx_buf_num);
   return 0;
 }
 
@@ -521,7 +521,7 @@
 	  rx -= j;
 
 	  DBG ("freed %d buffers. %u/%u alloc/free buffers",
-	       fb, rx, MAX_MEMIF_BUFS - rx);
+	       rx, rx, MAX_MEMIF_BUFS - rx);
 
 	  /* transmit allocated buffers */
 	  err = memif_tx_burst (c->conn, qid, c->tx_bufs, j, &tx);
@@ -545,7 +545,7 @@
     INFO ("memif_buffer_free: %s", memif_strerror (err));
   c->rx_buf_num -= rx;
   DBG ("freed %d buffers. %u/%u alloc/free buffers",
-       fb, c->rx_buf_num, MAX_MEMIF_BUFS - c->rx_buf_num);
+       rx, c->rx_buf_num, MAX_MEMIF_BUFS - c->rx_buf_num);
   return 0;
 }
 
@@ -612,7 +612,7 @@
     INFO ("memif_buffer_free: %s", memif_strerror (err));
   c->rx_buf_num -= rx;
   DBG ("freed %d buffers. %u/%u alloc/free buffers",
-       fb, c->rx_buf_num, MAX_MEMIF_BUFS - c->rx_buf_num);
+       rx, c->rx_buf_num, MAX_MEMIF_BUFS - c->rx_buf_num);
   return 0;
 }
 
diff --git a/extras/libmemif/examples/icmp_responder-mt/main.c b/extras/libmemif/examples/icmp_responder-mt/main.c
index bc2f71d..5c03823 100644
--- a/extras/libmemif/examples/icmp_responder-mt/main.c
+++ b/extras/libmemif/examples/icmp_responder-mt/main.c
@@ -565,7 +565,7 @@
 /* user needs to watch new fd or stop watching fd that is about to be closed.
     control fd will be modified during connection establishment to minimize CPU usage */
 int
-control_fd_update (int fd, uint8_t events)
+control_fd_update (int fd, uint8_t events, void *ctx)
 {
   /* convert memif event definitions to epoll events */
   if (events & MEMIF_FD_EVENT_DEL)
diff --git a/extras/libmemif/examples/icmp_responder-zero-copy-slave/main.c b/extras/libmemif/examples/icmp_responder-zero-copy-slave/main.c
index 7913588..b342c51 100644
--- a/extras/libmemif/examples/icmp_responder-zero-copy-slave/main.c
+++ b/extras/libmemif/examples/icmp_responder-zero-copy-slave/main.c
@@ -296,7 +296,7 @@
 /* user needs to watch new fd or stop watching fd that is about to be closed.
     control fd will be modified during connection establishment to minimize CPU usage */
 int
-control_fd_update (int fd, uint8_t events)
+control_fd_update (int fd, uint8_t events, void *ctx)
 {
   /* convert memif event definitions to epoll events */
   if (events & MEMIF_FD_EVENT_DEL)
@@ -371,7 +371,7 @@
       c->rx_buf_num -= rx;
 
       DBG ("freed %d buffers. %u/%u alloc/free buffers",
-	   fb, rx, MAX_MEMIF_BUFS - rx);
+	   rx, rx, MAX_MEMIF_BUFS - rx);
 
       /* transmit allocated buffers */
       err = memif_tx_burst (c->conn, qid, c->bufs, rx, &tx);
@@ -393,7 +393,7 @@
     INFO ("memif_buffer_free: %s", memif_strerror (err));
   c->rx_buf_num = 0;
   DBG ("freed %d buffers. %u/%u alloc/free buffers",
-       fb, c->rx_buf_num, MAX_MEMIF_BUFS - c->rx_buf_num);
+       rx, c->rx_buf_num, MAX_MEMIF_BUFS - c->rx_buf_num);
   return 0;
 }
 
@@ -450,7 +450,7 @@
       c->rx_buf_num -= rx;
 
       DBG ("freed %d buffers. %u/%u alloc/free buffers",
-	   fb, rx, MAX_MEMIF_BUFS - rx);
+	   rx, rx, MAX_MEMIF_BUFS - rx);
 
       /* transmit allocated buffers */
       err = memif_tx_burst (c->conn, qid, c->bufs, i, &tx);
@@ -472,7 +472,7 @@
     INFO ("memif_buffer_free: %s", memif_strerror (err));
   c->rx_buf_num = 0;
   DBG ("freed %d buffers. %u/%u alloc/free buffers",
-       fb, c->rx_buf_num, MAX_MEMIF_BUFS - c->rx_buf_num);
+       rx, c->rx_buf_num, MAX_MEMIF_BUFS - c->rx_buf_num);
   return 0;
 }
 
@@ -538,7 +538,7 @@
     INFO ("memif_buffer_free: %s", memif_strerror (err));
   c->rx_buf_num = 0;
   DBG ("freed %d buffers. %u/%u alloc/free buffers",
-       fb, c->rx_buf_num, MAX_MEMIF_BUFS - c->rx_buf_num);
+       rx, c->rx_buf_num, MAX_MEMIF_BUFS - c->rx_buf_num);
   return 0;
 }