diff --git a/gnu/services/web.scm b/gnu/services/web.scm
index 3b9f9e40be..e47acfe118 100644
--- a/gnu/services/web.scm
+++ b/gnu/services/web.scm
@@ -629,7 +629,7 @@ of index files."
                  modules
                  global-directives
                  extra-content)
-   (apply mixed-text-file "nginx.conf"
+   (apply mixed-text-file "unchecked-nginx.conf"
           (flatten
            "user nginx nginx;\n"
            "pid " run-directory "/pid;\n"
@@ -662,6 +662,19 @@ of index files."
            extra-content
            "\n}\n"))))
 
+(define (validated-nginx-configuration-file nginx file)
+  "Return a copy of FILE, an nginx config file, after checking that it is
+syntactically correct."
+  (computed-file "nginx.conf"
+                 (with-imported-modules '((guix build utils))
+                   #~(begin
+                       (use-modules (guix build utils))
+
+                       (mkdir "run")
+                       (invoke #+(file-append nginx "/sbin/nginx")
+                               "-c" #$file "-p" "run" "-t")
+                       (copy-file #$file #$output)))))
+
 (define %nginx-accounts
   (list (user-group (name "nginx") (system? #t))
         (user-account
@@ -694,8 +707,10 @@ of index files."
        (mkdir-p (string-append #$run-directory "/logs"))
        ;; Check configuration file syntax.
        (system* (string-append #$nginx "/sbin/nginx")
-                "-c" #$(or file
-                           (default-nginx-config config))
+                "-c" #$(validated-nginx-configuration-file
+                        nginx
+                        (or file
+                            (default-nginx-config config)))
                 "-p" #$run-directory
                 "-t"))))
 
@@ -709,8 +724,10 @@ of index files."
            (lambda args
              #~(lambda _
                  (invoke #$nginx-binary "-c"
-                         #$(or file
-                               (default-nginx-config config))
+                         #$(validated-nginx-configuration-file
+                            nginx
+                            (or file
+                                (default-nginx-config config)))
                          #$@args)
                  (match '#$args
                    (("-s" . _) #f)