diff --git a/find-external-requires b/find-external-requires
deleted file mode 100755
index d79db1d..0000000
--- a/find-external-requires
+++ /dev/null
@@ -1,23 +0,0 @@
-#!/bin/sh
-
-# Finds requirements provided outside of the current file set
-
-filelist=`sed "s/[]['\"*?{}]/\\\\\&/g"`
-
-provides=`echo $filelist | /usr/lib/rpm/find-provides`
-
-{
-for f in $filelist ; do
-	echo $f | /usr/lib/rpm/find-requires | while read req ; do
-		found=0
-		for p in $provides ; do
-			if [ "$req" = "$p" ]; then
-				found=1
-			fi
-		done
-		if [ "$found" = "0" ]; then
-			echo $req
-		fi
-	done
-done
-} | sort -u
\ No newline at end of file
diff --git a/thunderbird.spec b/thunderbird.spec
index 367731c..5dcee3b 100644
--- a/thunderbird.spec
+++ b/thunderbird.spec
@@ -67,7 +67,6 @@ Source11:       thunderbird-mozconfig-branded
 Source12:       thunderbird-redhat-default-prefs.js
 Source20:       thunderbird.desktop
 Source21:       thunderbird.sh.in
-Source100:      find-external-requires
 
 # Mozilla (XULRunner) patches
 Patch0:         thunderbird-install-dir.patch
@@ -136,7 +135,7 @@ Requires:       libvpx >= %{libvpx_version}
 
 AutoProv: 0
 %define _use_internal_dependency_generator 0
-%define __find_requires %{SOURCE100}
+%define __requires_exclude ^lib.*$
 
 %description
 Mozilla Thunderbird is a standalone mail and newsgroup client.