diff --git a/tools/tinderbox-configs/firefox/win32/mozconfig b/tools/tinderbox-configs/firefox/win32/mozconfig
index e618ab9e646..03fa01fbe1d 100644
--- a/tools/tinderbox-configs/firefox/win32/mozconfig
+++ b/tools/tinderbox-configs/firefox/win32/mozconfig
@@ -16,3 +16,4 @@ ac_add_options --enable-optimize
 ac_add_options --disable-debug
 ac_add_options --disable-tests
 ac_add_options --enable-update-packaging
+ac_add_options --enable-jemalloc