diff --git a/llvm-build/build.py b/llvm-build/build.py
index d135ff4dfb654358f94f9a66b935dc029dc1cd22..bef40a27305b806a335cc673709c4180a0112691 100755
--- a/llvm-build/build.py
+++ b/llvm-build/build.py
@@ -408,7 +408,7 @@ class BuildUtils(object):
                      install=True,
                      build_threads=False):
 
-        ninja_bin_path = os.path.join(self.CMAKE_BIN_DIR, 'ninja')
+        ninja_bin_path = os.path.join(self.build_config.REPOROOT_DIR, 'prebuilts/build-tools', self.platform_prefix(), 'bin', 'ninja')
 
         ninja_list = ['-l{}'.format(build_threads)] if build_threads else []
 
diff --git a/llvm-build/mingw.py b/llvm-build/mingw.py
index 9d27a5e1eb6e6d1b4cc2b2a3aa6036b28c3c3b4e..4436944af0646b2babb69c60d75c7cd4edbc8797 100755
--- a/llvm-build/mingw.py
+++ b/llvm-build/mingw.py
@@ -57,7 +57,7 @@ class LlvmMingw():
         self.build_config = build_config
 
         self.CMAKE_BIN_PATH = os.path.join(self.cmake_prebuilt_bin_dir(), 'cmake')
-        self.NINJA_BIN_PATH = os.path.join(self.cmake_prebuilt_bin_dir(), 'ninja')
+        self.NINJA_BIN_PATH = os.path.join(self.build_config.repo_root('prebuilts/build-tools', 'linux-x86', 'bin'), 'ninja')
 
         self.LLVM_ROOT = self.build_config.out_root('llvm-install')
         self.LLVM_CONFIG = os.path.join(self.LLVM_ROOT, 'bin', 'llvm-config')