diff --git a/pkgs/development/compilers/rust/rls/default.nix b/pkgs/development/compilers/rust/rls/default.nix
index 06b1b9b1e648..7534a52fe0f0 100644
--- a/pkgs/development/compilers/rust/rls/default.nix
+++ b/pkgs/development/compilers/rust/rls/default.nix
@@ -39,9 +39,9 @@ rustPlatform.buildRustPackage {
     $out/bin/rls --version
   '';
 
-  RUST_SRC_PATH = rustPlatform.rustcSrc;
+  RUST_SRC_PATH = rustPlatform.rustLibSrc;
   postInstall = ''
-    wrapProgram $out/bin/rls --set-default RUST_SRC_PATH ${rustPlatform.rustcSrc}
+    wrapProgram $out/bin/rls --set-default RUST_SRC_PATH ${rustPlatform.rustLibSrc}
   '';
 
   meta = with stdenv.lib; {