diff --git a/var/spack/repos/builtin/packages/root/package.py b/var/spack/repos/builtin/packages/root/package.py
index 74713d7d901b29beca8370ca166c2f3f23464810..afebc75de8ae4641e196f495f497ebcdb563ee83 100644
--- a/var/spack/repos/builtin/packages/root/package.py
+++ b/var/spack/repos/builtin/packages/root/package.py
@@ -244,7 +244,7 @@ class Root(CMakePackage):
     depends_on('vc',        when='+vc')
     depends_on('vdt',       when='+vdt')
     depends_on('libxml2',   when='+xml')
-    depends_on('xrootd',    when='+xrootd')
+    depends_on('xrootd@:4.99.99',    when='+xrootd')
 
     # ###################### Conflicts ######################
 
diff --git a/var/spack/repos/builtin/packages/xrootd/package.py b/var/spack/repos/builtin/packages/xrootd/package.py
index 6caa6eec04661d98ab03a9de0782c220c359bb76..70292848d65655b2d5f6ba605fb9d27d09b292b4 100644
--- a/var/spack/repos/builtin/packages/xrootd/package.py
+++ b/var/spack/repos/builtin/packages/xrootd/package.py
@@ -14,7 +14,7 @@ class Xrootd(CMakePackage):
     url      = "http://xrootd.org/download/v5.0.1/xrootd-5.0.1.tar.gz"
 
     version('5.0.1', sha256='ff4462b0b61db4cc01dda0e26abdd78e43649ee7ac5e90f7a05b74328ff5ac83')
-    version('4.12.3', sha256='6f2ca1accc8d49d605706bb556777c753860bf46d845b1ee11393a5cb5987f15')
+    version('4.12.3', sha256='6f2ca1accc8d49d605706bb556777c753860bf46d845b1ee11393a5cb5987f15', preferred=True)
     version('4.12.2', sha256='29f7bc3ea51b9d5d310eabd177152245d4160223325933c67f938ed5120f67bb')
     version('4.12.1', sha256='7350d9196a26d17719b839fd242849e3995692fda25f242e67ac6ec907218d13')
     version('4.12.0', sha256='69ef4732256d9a88127de4bfdf96bbf73348e0c70ce1d756264871a0ffadd2fc')