diff --git a/linux/build/build b/linux/build/build
index 003a608..e165e75 100755
--- a/linux/build/build
+++ b/linux/build/build
@@ -12,7 +12,7 @@ cd $dir
 
 arch=$(uname -m)
 language=$(echo $LANG | cut -c-5 | sed s/_/-/g)
-version="91.11.0esr"
+version="91.12.0esr"
 application="firefox"
 ftpmirror="https://ftp.mozilla.org/pub/$application/releases/$version"
 
diff --git a/macos/build/build b/macos/build/build
index 91e6292..165c710 100755
--- a/macos/build/build
+++ b/macos/build/build
@@ -12,7 +12,7 @@ cd $dir
 
 arch=$(uname -m)
 language=$(osascript -e 'user locale of (get system info)' | sed -e 's/_/-/g')
-version="91.11.0esr"
+version="91.12.0esr"
 i2pdversion="2.42.1"
 
 ftpmirror="https://ftp.mozilla.org/pub/firefox/releases/${version}"
diff --git a/windows/build/build.cmd b/windows/build/build.cmd
index cab5834..0615bf0 100644
--- a/windows/build/build.cmd
+++ b/windows/build/build.cmd
@@ -7,7 +7,7 @@ REM See full license text in LICENSE file at top of project tree
 setlocal enableextensions
 
 set CURL=%~dp0curl.exe
-set FFversion=91.11.0esr
+set FFversion=91.12.0esr
 set I2Pdversion=2.42.1
 call :GET_LOCALE
 call :GET_PROXY