--- a/servo/components/style/Cargo.toml
+++ b/servo/components/style/Cargo.toml
@@ -16,16 +16,17 @@ path = "lib.rs"
 doctest = false
 
 [features]
 gecko = ["nsstring_vendor", "num_cpus", "style_traits/gecko"]
 use_bindgen = ["bindgen", "regex", "toml"]
 servo = ["serde", "heapsize", "heapsize_derive",
          "style_traits/servo", "servo_atoms", "servo_config", "html5ever",
          "cssparser/heapsize", "cssparser/serde", "encoding", "smallvec/heapsizeof",
+         "string_cache",
 
          # FIXME: Uncomment when https://github.com/servo/servo/pull/16953 has landed:
          #"arrayvec/use_union"
 
          "servo_url"]
 testing = []
 gecko_debug = ["nsstring_vendor/gecko_debug"]
 
@@ -61,16 +62,17 @@ pdqsort = "0.1.0"
 precomputed-hash = "0.1"
 rayon = "0.8"
 selectors = { path = "../selectors" }
 serde = {version = "1.0", optional = true, features = ["derive"]}
 servo_arc = { path = "../servo_arc" }
 servo_atoms = {path = "../atoms", optional = true}
 servo_config = {path = "../config", optional = true}
 smallvec = "0.4"
+string_cache = {version = "0.6", optional = true}
 style_derive = {path = "../style_derive"}
 style_traits = {path = "../style_traits"}
 servo_url = {path = "../url", optional = true}
 time = "0.1"
 unicode-bidi = "0.3"
 unicode-segmentation = "1.0"
 
 [target.'cfg(windows)'.dependencies]

--- a/servo/components/style/lib.rs
+++ b/servo/components/style/lib.rs
@@ -75,16 +75,17 @@ extern crate precomputed_hash;
 extern crate rayon;
 extern crate selectors;
 #[cfg(feature = "servo")] #[macro_use] extern crate serde;
 pub extern crate servo_arc;
 #[cfg(feature = "servo")] #[macro_use] extern crate servo_atoms;
 #[cfg(feature = "servo")] extern crate servo_config;
 #[cfg(feature = "servo")] extern crate servo_url;
 extern crate smallvec;
+#[cfg(feature = "servo")] #[macro_use] extern crate string_cache;
 #[macro_use]
 extern crate style_derive;
 #[macro_use]
 extern crate style_traits;
 extern crate time;
 extern crate unicode_bidi;
 #[allow(unused_extern_crates)]
 extern crate unicode_segmentation;