diff --git a/pkgs/development/compilers/llvm/11/clang/default.nix b/pkgs/development/compilers/llvm/11/clang/default.nix
index 3aa3ba0ee46..53292ef844b 100644
--- a/pkgs/development/compilers/llvm/11/clang/default.nix
+++ b/pkgs/development/compilers/llvm/11/clang/default.nix
@@ -9,6 +9,7 @@ let
     inherit version;
 
     src = fetch "clang" "1p64l5a3x55118nyms1805qbk3r9w37nz1rb7xvbgc9fmyzaffay";
+    inherit clang-tools-extra_src;
 
     unpackPhase = ''
       unpackFile $src