diff --git a/build-aux/hydra/gnu-system.scm b/build-aux/hydra/gnu-system.scm
index 8206be22ff..abc107cb1c 100644
--- a/build-aux/hydra/gnu-system.scm
+++ b/build-aux/hydra/gnu-system.scm
@@ -58,7 +58,8 @@
 (define* (package->alist store package system
                          #:optional (package-derivation package-derivation))
   "Convert PACKAGE to an alist suitable for Hydra."
-  `((derivation . ,(package-derivation store package system))
+  `((derivation . ,(derivation-file-name
+                    (package-derivation store package system)))
     (description . ,(package-synopsis package))
     (long-description . ,(package-description package))
     (license . ,(package-license package))
diff --git a/build-aux/hydra/guix.scm b/build-aux/hydra/guix.scm
index 59e3172e1f..189b973a69 100644
--- a/build-aux/hydra/guix.scm
+++ b/build-aux/hydra/guix.scm
@@ -56,7 +56,8 @@
 (define* (package->alist store package system
                          #:optional (package-derivation package-derivation))
   "Convert PACKAGE to an alist suitable for Hydra."
-  `((derivation . ,(package-derivation store package system))
+  `((derivation . ,(derivation-file-name
+                    (package-derivation store package system)))
     (description . ,(package-synopsis package))
     (long-description . ,(package-description package))
     (license . ,(package-license package))