diff --git a/guix-data-service/branch-updated-emails.scm b/guix-data-service/branch-updated-emails.scm
index aeb1570..2c0e992 100644
--- a/guix-data-service/branch-updated-emails.scm
+++ b/guix-data-service/branch-updated-emails.scm
@@ -59,12 +59,10 @@
                  conn
                  git-repository-id)))
             (let ((excluded-branch?
-                   (branch-in-list? excluded-branches branch-name))
-                  (included-branch?
-                   (branch-in-list? included-branches branch-name)))
+                   (branch-in-list? excluded-branches branch-name)))
               (when (and (not excluded-branch?)
-                         (or (null? included-branches)
-                             included-branch?))
+                         (or (NULL? included-branches)
+                             (branch-in-list? included-branches branch-name)))
                 (if (string=? commit-all-zeros x-git-newrev)
                     (insert-git-commit-entry conn
                                              (or (git-branch-for-repository-and-name
diff --git a/guix-data-service/model/git-repository.scm b/guix-data-service/model/git-repository.scm
index c05376f..b5f9fbe 100644
--- a/guix-data-service/model/git-repository.scm
+++ b/guix-data-service/model/git-repository.scm
@@ -139,7 +139,7 @@ WHERE id = $1"
            item))
      lst))
 
-  (match (exec-query
+  (match (exec-query-with-null-handling
           conn
           "
 SELECT included_branches, excluded_branches
@@ -147,13 +147,11 @@ FROM git_repositories WHERE id = $1"
           (list (number->string id)))
     (((included_branches excluded_branches))
      (values
-      (if (or (eq? #f included_branches)
-              (string-null? included_branches))
-          '()
+      (if (NULL? included_branches)
+          included_branches
           (make-regexes
            (parse-postgresql-array-string included_branches)))
-      (if (or (eq? excluded_branches #f)
-              (string-null? excluded_branches))
+      (if (NULL? excluded_branches)
           '()
           (make-regexes
            (parse-postgresql-array-string excluded_branches)))))))
diff --git a/guix-data-service/poll-git-repository.scm b/guix-data-service/poll-git-repository.scm
index 8dfd13d..bff0de0 100644
--- a/guix-data-service/poll-git-repository.scm
+++ b/guix-data-service/poll-git-repository.scm
@@ -182,12 +182,10 @@
                   (filter
                    (lambda (branch-name)
                      (let ((excluded-branch?
-                            (branch-in-list? excluded-branches branch-name))
-                           (included-branch?
-                            (branch-in-list? included-branches branch-name)))
+                            (branch-in-list? excluded-branches branch-name)))
                        (and (not excluded-branch?)
-                            (or (null? included-branches)
-                                included-branch?))))
+                            (or (NULL? included-branches)
+                                (branch-in-list? included-branches branch-name)))))
                    (delete-duplicates!
                     (append!
                      (map car repository-branches)