diff --git a/conf.d/global.conf b/conf.d/global.conf
index 02ef4dab7bb5ea89d4d29a0998cde31871832ef6..a6472ba8106cc83f9d9a0d16543b2b1ea070dd28 100644
--- a/conf.d/global.conf
+++ b/conf.d/global.conf
@@ -1,7 +1,11 @@
 # The resolver for the Docker network.
-resolver        127.0.0.11 valid=30s;
-gzip            on;
-tcp_nopush      on;
-tcp_nodelay     on;
-server_tokens   off;
-include         snippets/common-headers.conf;
+resolver                        127.0.0.11 valid=30s;
+gzip                            on;
+tcp_nopush                      on;
+tcp_nodelay                     on;
+server_tokens                   off;
+include                         snippets/common-headers.conf;
+# Validate proxied SSL connections.
+proxy_ssl_trusted_certificate   /etc/ssl/certs/ca-certificates.crt;
+proxy_ssl_verify                on;
+proxy_ssl_verify_depth          4;