diff --git a/layout/reftests/svg/reftest.list b/layout/reftests/svg/reftest.list
index e5f1c63362fb..defc9e79db97 100644
--- a/layout/reftests/svg/reftest.list
+++ b/layout/reftests/svg/reftest.list
@@ -8,8 +8,7 @@ include sizing/reftest.list
 include filters/reftest.list
 
 # smil / animation tests
-# disabled because SMIL is not built by default
-# include smil/reftest.list
+include smil/reftest.list
 
 # Mozilla only tests (i.e. those containing XUL/XBL/etc.)
 include moz-only/reftest.list
diff --git a/modules/libpref/src/init/all.js b/modules/libpref/src/init/all.js
index 1614a256adf9..d493b05a0126 100644
--- a/modules/libpref/src/init/all.js
+++ b/modules/libpref/src/init/all.js
@@ -1202,7 +1202,7 @@ pref("dom.max_chrome_script_run_time", 20);
 pref("dom.max_script_run_time", 10);
 
 pref("svg.enabled", true);
-pref("svg.smil.enabled", false);
+pref("svg.smil.enabled", true);
 
 pref("font.minimum-size.ar", 0);
 pref("font.minimum-size.x-armn", 0);