diff --git a/testing/firefox/checksums b/testing/firefox/checksums
index 6c44d9249..cc65f80ce 100644
--- a/testing/firefox/checksums
+++ b/testing/firefox/checksums
@@ -1,4 +1,4 @@
-21bc680fcb48d80a37532a26ccaa11e8ae4198b94bd4a485e4d471fc8d6a346d  firefox-73.0b2.source.tar.xz
+ac3897f5316a8aa21ac5e73d595db27dbd1f6eca32aa7084fbe47bc7b41785ff  firefox-73.0b3.source.tar.xz
 f0611136bee505811e9ca11ca7ac188ef5323a8e2ef19cffd3edb3cf08fd791e  autoconf-2.13.tar.gz
 b5e70b12cc9dd18fffd7924a7d3a2e11574136fe0764359d08eba0755f1c5d4c  mozconfig
 960d82bbfdc88c95f5cb4f2e1c1bf23dae7519b3b7203914d7b3ddbff1ba4c28  stab.h
diff --git a/testing/firefox/sources b/testing/firefox/sources
index e77c9a544..67ac874af 100644
--- a/testing/firefox/sources
+++ b/testing/firefox/sources
@@ -1,4 +1,4 @@
-https://archive.mozilla.org/pub/firefox/releases/73.0b2/source/firefox-73.0b2.source.tar.xz
+https://archive.mozilla.org/pub/firefox/releases/73.0b3/source/firefox-73.0b3.source.tar.xz
 https://ftp.gnu.org/gnu/autoconf/autoconf-2.13.tar.gz autoconf2.13/
 files/mozconfig
 files/stab.h toolkit/crashreporter/google-breakpad/src/
diff --git a/testing/firefox/version b/testing/firefox/version
index ba992513a..31a4db945 100644
--- a/testing/firefox/version
+++ b/testing/firefox/version
@@ -1 +1 @@
-73.0b2 1
+73.0b3 1