diff -r 6c4f1ff135d3 -r d91c918a6511 MozillaFirefox/MozillaFirefox.spec
--- a/MozillaFirefox/MozillaFirefox.spec	Mon Mar 20 17:19:31 2017 +0100
+++ b/MozillaFirefox/MozillaFirefox.spec	Wed Mar 22 08:30:12 2017 +0100
@@ -92,6 +92,7 @@
 BuildRequires:  yasm
 BuildRequires:  zip
 BuildRequires:  pkgconfig(libpulse)
+BuildRequires:  pkgconfig(libffi)
 %if 0%{?firefox_use_gtk3}
 BuildRequires:  pkgconfig(glib-2.0)
 BuildRequires:  pkgconfig(gobject-2.0)