diff --git a/guix-data-service/web/server.scm b/guix-data-service/web/server.scm
index 9e20118..3719b9c 100644
--- a/guix-data-service/web/server.scm
+++ b/guix-data-service/web/server.scm
@@ -195,6 +195,8 @@ port. Also, the port used can be changed by passing the --port option.\n"
                        #:destructor
                        (lambda (conn)
                          (close-postgresql-connection conn "web"))
+                       #:add-resources-parallelism
+                       (floor (/ postgresql-connections 2))
                        #:default-max-waiters (floor (/ postgresql-connections 2))
                        #:default-checkout-timeout (/ postgresql-statement-timeout
                                                      1000)))
@@ -211,6 +213,8 @@ port. Also, the port used can be changed by passing the --port option.\n"
                        #:destructor
                        (lambda (conn)
                          (close-postgresql-connection conn "web-reserved"))
+                       #:add-resources-parallelism
+                       (floor (/ postgresql-connections 2))
                        #:default-max-waiters postgresql-connections
                        #:default-checkout-timeout 6)))