diff --git a/Cargo.lock b/Cargo.lock
index a61aec4e12..79e6329076 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1117,6 +1117,7 @@ dependencies = [
  "chalk-ir 0.1.0 (git+https://github.com/flodiebold/chalk.git?branch=fuel)",
  "chalk-rust-ir 0.1.0 (git+https://github.com/flodiebold/chalk.git?branch=fuel)",
  "chalk-solve 0.1.0 (git+https://github.com/flodiebold/chalk.git?branch=fuel)",
+ "either 1.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "ena 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "flexi_logger 0.11.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "insta 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/crates/ra_hir/Cargo.toml b/crates/ra_hir/Cargo.toml
index 294d047d89..18ecb79575 100644
--- a/crates/ra_hir/Cargo.toml
+++ b/crates/ra_hir/Cargo.toml
@@ -12,6 +12,7 @@ rustc-hash = "1.0"
 parking_lot = "0.7.0"
 ena = "0.11"
 join_to_string = "0.1.3"
+either = "1.5.2"
 
 ra_syntax = { path = "../ra_syntax" }
 ra_arena = { path = "../ra_arena" }