diff --git a/extra/firefox/.SRCINFO b/extra/firefox/.SRCINFO
index 9255ad756..c7f9facdd 100644
--- a/extra/firefox/.SRCINFO
+++ b/extra/firefox/.SRCINFO
@@ -1,6 +1,6 @@
 pkgbase = firefox
 	pkgdesc = Standalone web browser from mozilla.org
-	pkgver = 120.0.1
+	pkgver = 121.0
 	pkgrel = 1
 	url = https://www.mozilla.org/firefox/
 	arch = x86_64
@@ -49,16 +49,16 @@ pkgbase = firefox
 	options = !lto
 	options = !makeflags
 	options = !strip
-	source = https://archive.mozilla.org/pub/firefox/releases/120.0.1/source/firefox-120.0.1.source.tar.xz
-	source = https://archive.mozilla.org/pub/firefox/releases/120.0.1/source/firefox-120.0.1.source.tar.xz.asc
+	source = https://archive.mozilla.org/pub/firefox/releases/121.0/source/firefox-121.0.source.tar.xz
+	source = https://archive.mozilla.org/pub/firefox/releases/121.0/source/firefox-121.0.source.tar.xz.asc
 	source = firefox.desktop
 	source = identity-icons-brand.svg
 	validpgpkeys = 14F26682D0916CDD81E37B6D61B7B526D98F0353
-	sha256sums = 76e7bb2a144880158444d8e9014f4d080d219bd150c3db405b27e4c7e3959ae2
+	sha256sums = edc7a5159d23ff2a23e22bf5abe22231658cee2902b93b5889ee73958aa06aa4
 	sha256sums = SKIP
 	sha256sums = 1f241fdc619f92a914c75aece7c7c717401d7467c9a306458e106b05f34e5044
 	sha256sums = a9b8b4a0a1f4a7b4af77d5fc70c2686d624038909263c795ecc81e0aec7711e9
-	b2sums = 66ac2f1071ad8276b61946465db6d71cbe0a43c154fb57db67670e8f88183893fe7c7c8284388242964fd2883e50f40f29c879ebec3a2d759d20c356f27ca151
+	b2sums = 80905caeb208ef5dce7b62e248c86598ca786eb7032e114ad5d10812623bfceb688832f646dfbe220ef2fcecacf11cefae2afb0f1cdc0f7952647b71c58c9602
 	b2sums = SKIP
 	b2sums = d07557840097dd48a60c51cc5111950781e1c6ce255557693bd11306c7a9258b2a82548329762148f117b2295145f9e66e0483a18e2fe09c5afcffed2e4b8628
 	b2sums = 63a8dd9d8910f9efb353bed452d8b4b2a2da435857ccee083fc0c557f8c4c1339ca593b463db320f70387a1b63f1a79e709e9d12c69520993e26d85a3d742e34
diff --git a/extra/firefox/PKGBUILD b/extra/firefox/PKGBUILD
index 9760b09a4..fd033c074 100644
--- a/extra/firefox/PKGBUILD
+++ b/extra/firefox/PKGBUILD
@@ -10,7 +10,7 @@
 highmem=1
 
 pkgname=firefox
-pkgver=120.0.1
+pkgver=121.0
 pkgrel=1
 pkgdesc="Standalone web browser from mozilla.org"
 url="https://www.mozilla.org/firefox/"
@@ -76,11 +76,11 @@ validpgpkeys=(
   # https://blog.mozilla.org/security/2023/05/11/updated-gpg-key-for-signing-firefox-releases/
   14F26682D0916CDD81E37B6D61B7B526D98F0353
 )
-sha256sums=('76e7bb2a144880158444d8e9014f4d080d219bd150c3db405b27e4c7e3959ae2'
+sha256sums=('edc7a5159d23ff2a23e22bf5abe22231658cee2902b93b5889ee73958aa06aa4'
             'SKIP'
             '1f241fdc619f92a914c75aece7c7c717401d7467c9a306458e106b05f34e5044'
             'a9b8b4a0a1f4a7b4af77d5fc70c2686d624038909263c795ecc81e0aec7711e9')
-b2sums=('66ac2f1071ad8276b61946465db6d71cbe0a43c154fb57db67670e8f88183893fe7c7c8284388242964fd2883e50f40f29c879ebec3a2d759d20c356f27ca151'
+b2sums=('80905caeb208ef5dce7b62e248c86598ca786eb7032e114ad5d10812623bfceb688832f646dfbe220ef2fcecacf11cefae2afb0f1cdc0f7952647b71c58c9602'
         'SKIP'
         'd07557840097dd48a60c51cc5111950781e1c6ce255557693bd11306c7a9258b2a82548329762148f117b2295145f9e66e0483a18e2fe09c5afcffed2e4b8628'
         '63a8dd9d8910f9efb353bed452d8b4b2a2da435857ccee083fc0c557f8c4c1339ca593b463db320f70387a1b63f1a79e709e9d12c69520993e26d85a3d742e34')
@@ -174,10 +174,11 @@ END
 build() {
   cd firefox-$pkgver
 
-  export MOZ_NOSPAM=1
-  export MOZBUILD_STATE_PATH="$srcdir/mozbuild"
-  export MOZ_ENABLE_FULL_SYMBOLS=1
   export MACH_BUILD_PYTHON_NATIVE_PACKAGE_SOURCE=pip
+  export MOZBUILD_STATE_PATH="$srcdir/mozbuild"
+  export MOZ_BUILD_DATE="$(date -u${SOURCE_DATE_EPOCH:+d @$SOURCE_DATE_EPOCH} +%Y%m%d%H%M%S)"
+  export MOZ_ENABLE_FULL_SYMBOLS=1
+  export MOZ_NOSPAM=1
 
   # malloc_usable_size is used in various parts of the codebase
   CFLAGS="${CFLAGS/_FORTIFY_SOURCE=3/_FORTIFY_SOURCE=2}"