diff --git a/esc.spec b/esc.spec
index e6d6ede..11f1ec8 100644
--- a/esc.spec
+++ b/esc.spec
@@ -23,7 +23,8 @@ Requires: pcsc-lite ifd-egate coolkey
 Requires: gtk+ freetype zip nspr nss
 
 # 390 does not have coolkey or smartCards
-ExcludeArch: s390 s390x
+# Xulrunner won't compile on ppc64 right now.
+ExcludeArch: s390 s390x ppc64
 
 #%define __prelink_undo_cmd %{nil}
 %define escname %{name}-%{version}