diff --git a/mysql-test/main/bad_startup_options_debug.result b/mysql-test/main/bad_startup_options_debug.result
new file mode 100644
index 00000000000..626d9337d2b
--- /dev/null
+++ b/mysql-test/main/bad_startup_options_debug.result
@@ -0,0 +1,7 @@
+#
+# MDEV-34437 SIGSEGV in vio_get_normalized_ip when using extra-port
+#
+FOUND 1 /\[ERROR\] Can't create IP socket: Servname not supported/ in errorlog.err
+FOUND 1 /\[ERROR\] Can't create IP socket: Servname not supported/ in errorlog.err
+# restart
+# End of 10.11 tests
diff --git a/mysql-test/main/bad_startup_options_debug.test b/mysql-test/main/bad_startup_options_debug.test
new file mode 100644
index 00000000000..c43124eba39
--- /dev/null
+++ b/mysql-test/main/bad_startup_options_debug.test
@@ -0,0 +1,34 @@
+# mysqld refuses to run as root normally.
+--source include/not_as_root.inc
+--source include/have_debug.inc
+--source include/not_embedded.inc
+--source include/linux.inc
+
+--source include/shutdown_mysqld.inc
+
+# Try to start the server, with bad values for some options.
+# Make sure, the starts fails, and expected message is in the error log
+
+--let errorlog=$MYSQL_TMP_DIR/errorlog.err
+--let SEARCH_FILE=$errorlog
+
+--echo #
+--echo # MDEV-34437 SIGSEGV in vio_get_normalized_ip when using extra-port
+--echo #
+
+# getaddrinfo failure by fixing port to invalid value
+--error 1
+--exec $MYSQLD --defaults-group-suffix=.1 --defaults-file=$MYSQLTEST_VARDIR/my.cnf --debug='d,sabotage_port_number' --log-error=$errorlog
+--let SEARCH_PATTERN=\[ERROR\] Can't create IP socket: Servname not supported
+--source include/search_pattern_in_file.inc
+--remove_file $SEARCH_FILE
+
+--error 1
+--exec $MYSQLD --defaults-group-suffix=.1 --defaults-file=$MYSQLTEST_VARDIR/my.cnf --debug='d,sabotage_port_number' --bind-address=0.0.0.0 --log-error=$errorlog
+--let SEARCH_PATTERN=\[ERROR\] Can't create IP socket: Servname not supported
+--source include/search_pattern_in_file.inc
+--remove_file $SEARCH_FILE
+
+--source include/start_mysqld.inc
+
+--echo # End of 10.11 tests
diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index 890fe8cf87e..d1d32fc77fe 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -2329,6 +2329,7 @@ static void activate_tcp_port(uint port,
   else
     real_bind_addr_str= my_bind_addr_str;
 
+  DBUG_EXECUTE_IF("sabotage_port_number", port= UINT_MAX32;);
   my_snprintf(port_buf, NI_MAXSERV, "%d", port);
 
   if (real_bind_addr_str && *real_bind_addr_str)
@@ -2372,6 +2373,13 @@ static void activate_tcp_port(uint port,
   else
   {
     error= getaddrinfo(real_bind_addr_str, port_buf, &hints, &ai);
+    if (unlikely(error != 0))
+    {
+      sql_print_error("%s: %s", ER_DEFAULT(ER_IPSOCK_ERROR),
+                      gai_strerror(error));
+      unireg_abort(1); /* purecov: tested */
+    }
+
     head= ai;
   }