diff --git a/moz.configure b/moz.configure
index 443558c58e1f..d65f2546b5e2 100755
--- a/moz.configure
+++ b/moz.configure
@@ -558,7 +558,7 @@ def makensis_progs(target):
 
     return tuple(candidates)
 
-nsis = check_prog('MAKENSISU', makensis_progs, allow_missing=True)
+nsis = check_prog('MAKENSISU', makensis_progs)
 
 # Make sure the version of makensis is up to date.
 @depends_if(nsis)