diff --git a/CMakeLists.txt b/CMakeLists.txt
index e4f601226d..15097b8473 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -588,8 +588,10 @@ set( CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${LLVM_BINARY_DIR}/lib${LLVM_LIBDIR_SUFFIX}
 
 set(CMAKE_BUILD_WITH_INSTALL_RPATH ON)
 if (APPLE)
-  set(CMAKE_INSTALL_NAME_DIR "@rpath")
-  set(CMAKE_INSTALL_RPATH "@executable_path/../lib")
+  if(NOT DEFINED CMAKE_INSTALL_RPATH)
+    set(CMAKE_INSTALL_NAME_DIR "@rpath")
+    set(CMAKE_INSTALL_RPATH "@executable_path/../lib")
+    endif(NOT DEFINED CMAKE_INSTALL_RPATH)
 else(UNIX)
   if(NOT DEFINED CMAKE_INSTALL_RPATH)
     set(CMAKE_INSTALL_RPATH "\$ORIGIN/../lib${LLVM_LIBDIR_SUFFIX}")
diff --git a/cmake/modules/HandleLLVMOptions.cmake b/cmake/modules/HandleLLVMOptions.cmake
index 984794e64e..709c89f6fc 100644
--- a/cmake/modules/HandleLLVMOptions.cmake
+++ b/cmake/modules/HandleLLVMOptions.cmake
@@ -78,6 +78,11 @@ if( LLVM_ENABLE_ASSERTIONS )
         "${flags_var_to_scrub}" "${${flags_var_to_scrub}}")
     endforeach()
   endif()
+else()
+  # Disable assertions in Debug builds
+  if( uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
+    add_definitions( -DNDEBUG )
+  endif()
 endif()
 
 string(TOUPPER "${LLVM_ABI_BREAKING_CHECKS}" uppercase_LLVM_ABI_BREAKING_CHECKS)
diff --git a/external/CMakeLists.txt b/external/CMakeLists.txt
index b779739856..ba1a5db603 100644
--- a/external/CMakeLists.txt
+++ b/external/CMakeLists.txt
@@ -8,13 +8,15 @@ if (NOT HLSL_ENABLE_DEBUG_ITERATORS)
 endif (NOT HLSL_ENABLE_DEBUG_ITERATORS)
 
 # Need DirectX-Headers module if not on windows
-if (NOT WIN32)
-  if (IS_DIRECTORY "${DXC_EXTERNAL_ROOT_DIR}/DirectX-Headers")
-    set(DIRECTX_HEADER_INCLUDE_DIR ${DXC_EXTERNAL_ROOT_DIR}/DirectX-Headers/include PARENT_SCOPE)
-  else()
-    message(FATAL_ERROR "DirectX-Headers was not found - required for reflection support on *nix see https://github.com/microsoft/DirectX-Headers")
-  endif()
-endif (NOT WIN32)
+if (NOT DIRECTX_HEADER_INCLUDE_DIR)
+  if (NOT WIN32)
+    if (IS_DIRECTORY "${DXC_EXTERNAL_ROOT_DIR}/DirectX-Headers")
+      set(DIRECTX_HEADER_INCLUDE_DIR ${DXC_EXTERNAL_ROOT_DIR}/DirectX-Headers/include PARENT_SCOPE)
+    else()
+      message(FATAL_ERROR "DirectX-Headers was not found - required for reflection support on *nix see https://github.com/microsoft/DirectX-Headers")
+    endif()
+  endif (NOT WIN32)
+endif(NOT DIRECTX_HEADER_INCLUDE_DIR)
 
 # Enabling SPIR-V codegen requires SPIRV-Headers for spirv.hpp and
 # SPIRV-Tools for SPIR-V disassembling functionality.