diff --git a/guix-data-service/web/revision/controller.scm b/guix-data-service/web/revision/controller.scm
index 0739b78..a64d314 100644
--- a/guix-data-service/web/revision/controller.scm
+++ b/guix-data-service/web/revision/controller.scm
@@ -993,28 +993,34 @@
            '(application/json text/html)
            mime-types)
       ((application/json)
-       (render-json
-        `((name . ,name)
-          (version . ,version)
-          ,@(match metadata
-              (((synopsis synopsis-locale description description-locale home-page file line column-number
-                          licenses))
-               `((synopsis . ,(texinfo->variants-alist synopsis synopsis-locale))
-                 (description . ,(texinfo->variants-alist description description-locale))
-                 (location
-                  . ((file   . ,file)
-                     (line   . ,line)
-                     (column . ,column-number)))
-                 (home-page . ,home-page))))
-          (derivations . ,(list->vector
-                           (map (match-lambda
-                                  ((system target file-name status outputs)
-                                   `((system . ,system)
-                                     (target . ,target)
-                                     (derivation . ,file-name)
-                                     (outputs . ,(list->vector outputs)))))
-                                derivations))))
-        #:extra-headers http-headers-for-unchanging-content))
+       (if (null? metadata)
+           (render-json
+            `((name . ,name)
+              (version . ,version)
+              (error . "package not found"))
+            #:code 404)
+           (render-json
+            `((name . ,name)
+              (version . ,version)
+              ,@(match metadata
+                  (((synopsis synopsis-locale description description-locale home-page file line column-number
+                              licenses))
+                   `((synopsis . ,(texinfo->variants-alist synopsis synopsis-locale))
+                     (description . ,(texinfo->variants-alist description description-locale))
+                     (location
+                      . ((file   . ,file)
+                         (line   . ,line)
+                         (column . ,column-number)))
+                     (home-page . ,home-page))))
+              (derivations . ,(list->vector
+                               (map (match-lambda
+                                      ((system target file-name status outputs)
+                                       `((system . ,system)
+                                         (target . ,target)
+                                         (derivation . ,file-name)
+                                         (outputs . ,(list->vector outputs)))))
+                                    derivations))))
+            #:extra-headers http-headers-for-unchanging-content)))
       (else
        (render-html
         #:sxml (view-revision-package-and-version commit-hash
@@ -1030,6 +1036,9 @@
                                                   #:header-link header-link
                                                   #:version-history-link
                                                   version-history-link)
+        #:code (if (null? metadata)
+                   404
+                   200)
         #:extra-headers http-headers-for-unchanging-content)))))
 
 (define* (render-revision-package-derivations mime-types
diff --git a/guix-data-service/web/revision/html.scm b/guix-data-service/web/revision/html.scm
index 04133ad..45d1fc5 100644
--- a/guix-data-service/web/revision/html.scm
+++ b/guix-data-service/web/revision/html.scm
@@ -243,6 +243,8 @@
        (div
         (@ (class "col-sm-12"))
         ,(match package-metadata
+           (()
+            "Package not found at this version")
            (((synopsis synopsis-locale description description-locale home-page file line column-number
                        licenses))
             `(dl