--- a/browser/config/mozconfigs/linux32/nightly
+++ b/browser/config/mozconfigs/linux32/nightly
@@ -1,10 +1,13 @@
 . "$topsrcdir/browser/config/mozconfigs/linux32/common-opt"
 
+# Enabled to get some telemetry
+mk_add_options "export JAR_COMPRESSION=brotli"
+
 ac_add_options --enable-profiling
 ac_add_options --enable-verify-mar
 
 # This will overwrite the default of stripping everything and keep the symbol table.
 # This is useful for profiling and debugging and only increases the package size
 # by 2 MBs.
 STRIP_FLAGS="--strip-debug"
 

--- a/browser/config/mozconfigs/linux64/nightly
+++ b/browser/config/mozconfigs/linux64/nightly
@@ -1,10 +1,13 @@
 . "$topsrcdir/browser/config/mozconfigs/linux64/common-opt"
 
+# Enabled to get some telemetry
+mk_add_options "export JAR_COMPRESSION=brotli"
+
 ac_add_options --enable-profiling
 ac_add_options --enable-verify-mar
 
 # This will overwrite the default of stripping everything and keep the symbol table.
 # This is useful for profiling and debugging and only increases the package size
 # by 2 MBs.
 STRIP_FLAGS="--strip-debug"
 

--- a/browser/config/mozconfigs/macosx64/nightly
+++ b/browser/config/mozconfigs/macosx64/nightly
@@ -1,10 +1,13 @@
 . "$topsrcdir/browser/config/mozconfigs/macosx64/common-opt"
 
+# Enabled to get some telemetry
+mk_add_options "export JAR_COMPRESSION=brotli"
+
 ac_add_options --disable-install-strip
 ac_add_options --enable-verify-mar
 ac_add_options --enable-profiling
 ac_add_options --enable-instruments
 
 # Cross-compiled builds fail when dtrace is enabled
 if test `uname -s` != Linux; then
   ac_add_options --enable-dtrace

--- a/browser/config/mozconfigs/whitelist
+++ b/browser/config/mozconfigs/whitelist
@@ -7,16 +7,17 @@ whitelist = {
 
 all_platforms = ['win64', 'win32', 'linux32', 'linux64', 'macosx64']
 
 for platform in all_platforms:
     whitelist['nightly'][platform] = [
         'ac_add_options --enable-update-channel=nightly',
         'ac_add_options --with-branding=browser/branding/nightly',
         'ac_add_options --enable-profiling',
+        'mk_add_options "export JAR_COMPRESSION=brotli"',
         'mk_add_options CLIENT_PY_ARGS="--hg-options=\'--verbose --time\' --hgtool=../tools/buildfarm/utils/hgtool.py --skip-chatzilla --skip-comm --skip-inspector --tinderbox-print"'
     ]
 
 for platform in ['linux32', 'linux64', 'macosx64']:
     whitelist['nightly'][platform] += [
         'mk_add_options MOZ_MAKE_FLAGS="-j4"',
     ]
 

--- a/browser/config/mozconfigs/win32/nightly
+++ b/browser/config/mozconfigs/win32/nightly
@@ -1,9 +1,12 @@
 . "$topsrcdir/build/mozconfig.win-common"
 . "$topsrcdir/browser/config/mozconfigs/win32/common-opt"
 
+# Enabled to get some telemetry
+mk_add_options "export JAR_COMPRESSION=brotli"
+
 ac_add_options --enable-profiling
 ac_add_options --enable-verify-mar
 
 ac_add_options --with-branding=browser/branding/nightly
 
 . "$topsrcdir/build/mozconfig.common.override"

--- a/browser/config/mozconfigs/win64/nightly
+++ b/browser/config/mozconfigs/win64/nightly
@@ -1,10 +1,13 @@
 . "$topsrcdir/build/mozconfig.win-common"
 . "$topsrcdir/browser/config/mozconfigs/win64/common-win64"
 . "$topsrcdir/browser/config/mozconfigs/win64/common-opt"
 
+# Enabled to get some telemetry
+mk_add_options "export JAR_COMPRESSION=brotli"
+
 ac_add_options --enable-profiling
 ac_add_options --enable-verify-mar
 
 ac_add_options --with-branding=browser/branding/nightly
 
 . "$topsrcdir/build/mozconfig.common.override"