diff --git a/include/proto/connection.h b/include/proto/connection.h
index 397c4781f..8921a06fd 100644
--- a/include/proto/connection.h
+++ b/include/proto/connection.h
@@ -152,6 +152,7 @@ static inline void conn_force_close(struct connection *conn)
 	if (conn_ctrl_ready(conn))
 		fd_delete(conn->t.sock.fd);
 
+	conn->t.sock.fd = DEAD_FD_MAGIC;
 	conn->flags &= ~(CO_FL_XPRT_READY|CO_FL_CTRL_READY);
 }
 
@@ -481,7 +482,7 @@ static inline void conn_init(struct connection *conn)
 	conn->data = NULL;
 	conn->owner = NULL;
 	conn->send_proxy_ofs = 0;
-	conn->t.sock.fd = -1; /* just to help with debugging */
+	conn->t.sock.fd = DEAD_FD_MAGIC;
 	conn->err_code = CO_ER_NONE;
 	conn->target = NULL;
 	conn->proxy_netns = NULL;
diff --git a/include/types/fd.h b/include/types/fd.h
index 8299a0264..7f6309354 100644
--- a/include/types/fd.h
+++ b/include/types/fd.h
@@ -76,6 +76,19 @@ enum fd_states {
 	FD_ST_READY
 };
 
+
+/* This is the value used to mark a file descriptor as dead. This value is
+ * negative, this is important so that tests on fd < 0 properly match. It
+ * also has the nice property of being highly negative but not overflowing
+ * nor changing sign on 32-bit machines when multipled by sizeof(fdtab).
+ * This ensures that any unexpected dereference of such an uninitialized
+ * file descriptor will lead to so large a dereference that it will crash
+ * the process at the exact location of the bug with a clean stack trace
+ * instead of causing silent manipulation of other FDs. And it's readable
+ * when found in a dump.
+ */
+#define DEAD_FD_MAGIC 0xFDDEADFD
+
 /* info about one given fd */
 struct fdtab {
 	void (*iocb)(int fd);                /* I/O handler */
diff --git a/src/dumpstats.c b/src/dumpstats.c
index 5cc09aa22..4c3f83027 100644
--- a/src/dumpstats.c
+++ b/src/dumpstats.c
@@ -6088,13 +6088,15 @@ static int stats_dump_full_sess_to_buffer(struct stream_interface *si, struct st
 			              obj_type_name(conn->target),
 			              obj_base_ptr(conn->target));
 
-			chunk_appendf(&trash,
-			              "      flags=0x%08x fd=%d fd.state=%02x fd.cache=%d updt=%d\n",
-			              conn->flags,
-			              conn->t.sock.fd,
-			              conn->t.sock.fd >= 0 ? fdtab[conn->t.sock.fd].state : 0,
-			              conn->t.sock.fd >= 0 ? fdtab[conn->t.sock.fd].cache : 0,
-			              conn->t.sock.fd >= 0 ? fdtab[conn->t.sock.fd].updated : 0);
+			chunk_appendf(&trash, "      flags=0x%08x", conn->flags);
+
+			if (conn->t.sock.fd >= 0) {
+				chunk_appendf(&trash, " fd=%d fd.state=%02x fd.cache=%d updt=%d\n",
+				              conn->t.sock.fd, fdtab[conn->t.sock.fd].state,
+				              fdtab[conn->t.sock.fd].cache, fdtab[conn->t.sock.fd].updated);
+			}
+			else
+				chunk_appendf(&trash, " fd=<dead>\n");
 		}
 		else if ((tmpctx = objt_appctx(sess->si[0].end)) != NULL) {
 			chunk_appendf(&trash,
@@ -6116,13 +6118,15 @@ static int stats_dump_full_sess_to_buffer(struct stream_interface *si, struct st
 			              obj_type_name(conn->target),
 			              obj_base_ptr(conn->target));
 
-			chunk_appendf(&trash,
-			              "      flags=0x%08x fd=%d fd.state=%02x fd.cache=%d updt=%d\n",
-			              conn->flags,
-			              conn->t.sock.fd,
-			              conn->t.sock.fd >= 0 ? fdtab[conn->t.sock.fd].state : 0,
-			              conn->t.sock.fd >= 0 ? fdtab[conn->t.sock.fd].cache : 0,
-			              conn->t.sock.fd >= 0 ? fdtab[conn->t.sock.fd].updated : 0);
+			chunk_appendf(&trash, "      flags=0x%08x", conn->flags);
+
+			if (conn->t.sock.fd >= 0) {
+				chunk_appendf(&trash, " fd=%d fd.state=%02x fd.cache=%d updt=%d\n",
+				              conn->t.sock.fd, fdtab[conn->t.sock.fd].state,
+				              fdtab[conn->t.sock.fd].cache, fdtab[conn->t.sock.fd].updated);
+			}
+			else
+				chunk_appendf(&trash, " fd=<dead>\n");
 		}
 		else if ((tmpctx = objt_appctx(sess->si[1].end)) != NULL) {
 			chunk_appendf(&trash,
@@ -6688,7 +6692,7 @@ static int stats_dump_sess_to_buffer(struct stream_interface *si)
 				     " s0=[%d,%1xh,fd=%d,ex=%s]",
 				     curr_sess->si[0].state,
 				     curr_sess->si[0].flags,
-				     conn ? conn->t.sock.fd : -1,
+				     (conn && conn->t.sock.fd >= 0) ? conn->t.sock.fd : -1,
 				     curr_sess->si[0].exp ?
 				     human_time(TICKS_TO_MS(curr_sess->si[0].exp - now_ms),
 						TICKS_TO_MS(1000)) : "");
@@ -6698,7 +6702,7 @@ static int stats_dump_sess_to_buffer(struct stream_interface *si)
 				     " s1=[%d,%1xh,fd=%d,ex=%s]",
 				     curr_sess->si[1].state,
 				     curr_sess->si[1].flags,
-				     conn ? conn->t.sock.fd : -1,
+				     (conn && conn->t.sock.fd >= 0) ? conn->t.sock.fd : -1,
 				     curr_sess->si[1].exp ?
 				     human_time(TICKS_TO_MS(curr_sess->si[1].exp - now_ms),
 						TICKS_TO_MS(1000)) : "");