diff --git a/profiles/package.mask b/profiles/package.mask
index 337b78b8daf43..a5703541ebb33 100644
--- a/profiles/package.mask
+++ b/profiles/package.mask
@@ -29,6 +29,11 @@
 
 #--- END OF EXAMPLES ---
 
+# Andreas Sturmlechner <asturm@gentoo.org> (04 Mar 2018)
+# Dead upstream, depends on deprecated Qt4.
+# Masked for removal in 30 days. Bug 645436
+sci-chemistry/massxpert
+
 # Andreas Sturmlechner <asturm@gentoo.org> (04 Mar 2018)
 # Dead upstream, depends on deprecated Qt4.
 # Masked for removal in 30 days. Bug 514438, 644522