diff --git a/bolt/test/lit.cfg.py b/bolt/test/lit.cfg.py
--- a/bolt/test/lit.cfg.py
+++ b/bolt/test/lit.cfg.py
@@ -55,8 +55,10 @@
 
 llvm_config.use_default_substitutions()
 
-llvm_config.use_clang(additional_tool_dirs=[os.path.dirname(config.bolt_clang)])
-llvm_config.use_lld(additional_tool_dirs=[os.path.dirname(config.bolt_lld)])
+llvm_config.config.environment['BOLT_CLANG_EXE'] = config.bolt_clang
+llvm_config.config.environment['BOLT_LLD_EXE'] = config.bolt_lld
+llvm_config.use_clang(search_env='BOLT_CLANG_EXE')
+llvm_config.use_llvm_tool('lld', required=True, search_env='BOLT_LLD_EXE')
 
 config.substitutions.append(('%cflags', '-no-pie'))
 config.substitutions.append(('%cxxflags', '-no-pie'))
diff --git a/llvm/utils/lit/lit/llvm/config.py b/llvm/utils/lit/lit/llvm/config.py
--- a/llvm/utils/lit/lit/llvm/config.py
+++ b/llvm/utils/lit/lit/llvm/config.py
@@ -437,7 +437,7 @@
         return tool
 
     def use_clang(self, additional_tool_dirs=[], additional_flags=[],
-                  required=True, use_installed=False):
+                  required=True, use_installed=False, search_env='CLANG'):
         """Configure the test suite to be able to invoke clang.
 
         Sets up some environment variables important to clang, locates a
@@ -505,7 +505,7 @@
 
         # Discover the 'clang' and 'clangcc' to use.
         self.config.clang = self.use_llvm_tool(
-            'clang', search_env='CLANG', required=required,
+            'clang', search_env=search_env, required=required,
             search_paths=paths, use_installed=use_installed)
         if self.config.clang:
           self.config.available_features.add('clang')