Patch-Source: https://phabricator.services.mozilla.com/D212612

diff --git a/toolkit/moz.configure b/toolkit/moz.configure
index 6d5485325c..c5dcc65dd5 100644
--- a/toolkit/moz.configure
+++ b/toolkit/moz.configure
@@ -2426,6 +2426,8 @@ with only_when(compile_environment):
         & jpeg_arm_neon_vld1q_u8_x4,
     )
 
+    set_config("MOZ_SYSTEM_JPEG", True, when="--with-system-jpeg")
+
 
 # PNG
 # ===