diff --git a/nix/default.nix b/nix/default.nix
index 75c727763..140ae7fe7 100644
--- a/nix/default.nix
+++ b/nix/default.nix
@@ -75,11 +75,11 @@ let
         unifiedSystemDir = true;
       };
       rawhide = version: arch: repodata: import (pkgs.runCommand "rawhide-${version}-${arch}.nix" {} ''
-        sha=$(grep primary.xml ${repodata} | sed -re 's:.* ([0-9a-f]+)-primary.*:\1:')
+        sha=$(grep primary.xml ${repodata} | sed -re 's:.* ([0-9a-f]+)-primary.*:\1:' | head -n 1)
         echo '{fedora}: fedora { version = "${version}"; sha = "'$sha'"; arch = "${arch}"; }' > $out
       '') { inherit fedora; };
       update = version: arch: repodata: orig: orig // (import (pkgs.runCommand "updates-fedora.nix" {} ''
-          sha=$(grep primary.xml ${repodata} | sed -re 's:.* ([0-9a-f]+)-primary.*:\1:')
+          sha=$(grep primary.xml ${repodata} | sed -re 's:.* ([0-9a-f]+)-primary.*:\1:' | head -n 1)
           echo fedora ${version} updates sha: $sha
           (echo 'fetchurl: orig: { packagesLists = [ orig.packagesList ('
            echo "fetchurl { "