diff --git a/components/profile/Cargo.toml b/components/profile/Cargo.toml
index 7fbe3db8bca..a02914db61d 100644
--- a/components/profile/Cargo.toml
+++ b/components/profile/Cargo.toml
@@ -9,6 +9,9 @@ publish = false
 name = "profile"
 path = "lib.rs"
 
+[features]
+unstable = []
+
 [dependencies]
 profile_traits = {path = "../profile_traits"}
 influent = "0.4"
diff --git a/components/profile/lib.rs b/components/profile/lib.rs
index 5573907a1c9..96b8edb7e17 100644
--- a/components/profile/lib.rs
+++ b/components/profile/lib.rs
@@ -2,16 +2,17 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#![cfg_attr(not(target_os = "windows"), feature(alloc_jemalloc))]
+#![cfg_attr(all(feature = "unstable", not(target_os = "windows")), feature(alloc_jemalloc))]
 
 #![deny(unsafe_code)]
 
 #[allow(unused_extern_crates)]
-#[cfg(not(target_os = "windows"))]
+#[cfg(all(feature = "unstable", not(target_os = "windows")))]
 extern crate alloc_jemalloc;
 extern crate heartbeats_simple;
 extern crate influent;
 extern crate ipc_channel;
+#[allow(unused_extern_crates)]
 #[cfg(not(target_os = "windows"))]
 extern crate libc;
 #[macro_use]
diff --git a/components/profile/mem.rs b/components/profile/mem.rs
index 51d51fa23e9..39d3f3ad084 100644
--- a/components/profile/mem.rs
+++ b/components/profile/mem.rs
@@ -353,14 +353,16 @@ impl ReportsForest {
 //---------------------------------------------------------------------------
 
 mod system_reporter {
-    #[cfg(not(target_os = "windows"))]
-    use libc::{c_char, c_int, c_void, size_t};
+    #[cfg(all(feature = "unstable", not(target_os = "windows")))]
+    use libc::{c_char, c_void, size_t};
+    #[cfg(target_os = "linux")]
+    use libc::c_int;
     use profile_traits::mem::{Report, ReportKind, ReporterRequest};
-    #[cfg(not(target_os = "windows"))]
+    #[cfg(all(feature = "unstable", not(target_os = "windows")))]
     use std::ffi::CString;
-    #[cfg(not(target_os = "windows"))]
+    #[cfg(all(feature = "unstable", not(target_os = "windows")))]
     use std::mem::size_of;
-    #[cfg(not(target_os = "windows"))]
+    #[cfg(all(feature = "unstable", not(target_os = "windows")))]
     use std::ptr::null_mut;
     use super::{JEMALLOC_HEAP_ALLOCATED_STR, SYSTEM_HEAP_ALLOCATED_STR};
     #[cfg(target_os = "macos")]
@@ -457,14 +459,14 @@ mod system_reporter {
         None
     }
 
-    #[cfg(not(target_os = "windows"))]
+    #[cfg(all(feature = "unstable", not(target_os = "windows")))]
     extern {
         #[cfg_attr(any(target_os = "macos", target_os = "android"), link_name = "je_mallctl")]
         fn mallctl(name: *const c_char, oldp: *mut c_void, oldlenp: *mut size_t,
-                   newp: *mut c_void, newlen: size_t) -> c_int;
+                   newp: *mut c_void, newlen: size_t) -> ::libc::c_int;
     }
 
-    #[cfg(not(target_os = "windows"))]
+    #[cfg(all(feature = "unstable", not(target_os = "windows")))]
     fn jemalloc_stat(value_name: &str) -> Option<usize> {
         // Before we request the measurement of interest, we first send an "epoch"
         // request. Without that jemalloc gives cached statistics(!) which can be
@@ -500,7 +502,7 @@ mod system_reporter {
         Some(value as usize)
     }
 
-    #[cfg(target_os = "windows")]
+    #[cfg(any(target_os = "windows", not(feature = "unstable")))]
     fn jemalloc_stat(_value_name: &str) -> Option<usize> {
         None
     }
diff --git a/components/servo/Cargo.toml b/components/servo/Cargo.toml
index 016ccc43a76..18837d14078 100644
--- a/components/servo/Cargo.toml
+++ b/components/servo/Cargo.toml
@@ -26,6 +26,7 @@ unstable = [
     "compositing/unstable",
     "constellation/unstable",
     "gfx/unstable",
+    "profile/unstable",
 ]
 
 [dependencies]