diff --git a/components/servo/lib.rs b/components/servo/lib.rs
index 1682f0e8c2b..d4c1d4e44d3 100644
--- a/components/servo/lib.rs
+++ b/components/servo/lib.rs
@@ -78,8 +78,6 @@ pub struct Browser {
 impl Browser  {
     pub fn new<Window>(window: Option<Rc<Window>>) -> Browser
     where Window: WindowMethods + 'static {
-        ::util::opts::set_experimental_enabled(opts::get().enable_experimental);
-
         // Global configuration options, parsed from the command line.
         let opts = opts::get();
 
diff --git a/components/util/opts.rs b/components/util/opts.rs
index c806e19b4a0..3505b33f210 100644
--- a/components/util/opts.rs
+++ b/components/util/opts.rs
@@ -406,6 +406,9 @@ pub fn from_cmdline_args(args: &[String]) -> bool {
 
 static mut EXPERIMENTAL_ENABLED: bool = false;
 
+/// Turn on experimental features globally. Normally this is done
+/// during initialization by `set` or `from_cmdline_args`, but
+/// tests that require experimental features will also set it.
 pub fn set_experimental_enabled(new_value: bool) {
     unsafe {
         EXPERIMENTAL_ENABLED = new_value;
@@ -426,6 +429,7 @@ static mut OPTIONS: *mut Opts = 0 as *mut Opts;
 pub fn set(opts: Opts) {
     unsafe {
         assert!(OPTIONS.is_null());
+        set_experimental_enabled(opts.enable_experimental);
         let box_opts = box opts;
         OPTIONS = mem::transmute(box_opts);
     }
diff --git a/ports/gonk/src/lib.rs b/ports/gonk/src/lib.rs
index 3174c5294ee..0038ee8eeb6 100644
--- a/ports/gonk/src/lib.rs
+++ b/ports/gonk/src/lib.rs
@@ -78,7 +78,6 @@ impl Browser {
     #[cfg(not(test))]
     pub fn new<Window>(window: Option<Rc<Window>>) -> Browser
         where Window: WindowMethods + 'static {
-        ::util::opts::set_experimental_enabled(opts::get().enable_experimental);
         // Global configuration options, parsed from the command line.
         let opts = opts::get();