diff --git a/pkgs/development/compilers/llvm/3.8/llvm.nix b/pkgs/development/compilers/llvm/3.8/llvm.nix
index fcb4214a1de8..ca6723172d7a 100644
--- a/pkgs/development/compilers/llvm/3.8/llvm.nix
+++ b/pkgs/development/compilers/llvm/3.8/llvm.nix
@@ -49,7 +49,7 @@ in stdenv.mkDerivation rec {
     sed -i 's/os_trace(\(.*\)");$/printf(\1\\n");/g' ./projects/compiler-rt/lib/sanitizer_common/sanitizer_mac.cc
 
     substituteInPlace CMakeLists.txt \
-      --replace 'set(_install_name_dir INSTALL_NAME_DIR "@rpath")' "set(_install_name_dir)" \
+      --replace 'set(CMAKE_INSTALL_NAME_DIR "@rpath")' "set(CMAKE_INSTALL_NAME_DIR "$out/lib")" \
       --replace 'set(CMAKE_INSTALL_RPATH "@executable_path/../lib")' ""
   ''
   + ''
diff --git a/pkgs/development/compilers/llvm/3.9/llvm.nix b/pkgs/development/compilers/llvm/3.9/llvm.nix
index 00c56e49e374..678ec759425d 100644
--- a/pkgs/development/compilers/llvm/3.9/llvm.nix
+++ b/pkgs/development/compilers/llvm/3.9/llvm.nix
@@ -82,7 +82,7 @@ in stdenv.mkDerivation rec {
       --replace 'set(COMPILER_RT_HAS_TSAN TRUE)' 'set(COMPILER_RT_HAS_TSAN FALSE)'
 
     substituteInPlace CMakeLists.txt \
-      --replace 'set(_install_name_dir INSTALL_NAME_DIR "@rpath")' "set(_install_name_dir)" \
+      --replace 'set(CMAKE_INSTALL_NAME_DIR "@rpath")' "set(CMAKE_INSTALL_NAME_DIR "$lib/lib")" \
       --replace 'set(CMAKE_INSTALL_RPATH "@executable_path/../lib")' ""
   ''
   # Patch llvm-config to return correct library path based on --link-{shared,static}.