diff --git a/build.rs b/build.rs
index c83e7125..22535318 100644
--- a/build.rs
+++ b/build.rs
@@ -108,8 +108,19 @@ fn platform() -> &'static str {
 
 fn download_gn_ninja_binaries() {
   let root = env::current_dir().unwrap();
-  let out_dir = root.join(env::var_os("OUT_DIR").unwrap());
-  let d = out_dir.join("gn_ninja_binaries").join(platform());
+  // target/debug//build/rusty_v8-d9e5a424d4f96994/out/
+  let out_dir = env::var_os("OUT_DIR").unwrap();
+  let out_dir_abs = root.join(out_dir);
+  // This would be target/debug or target/release
+  let target_dir = out_dir_abs
+    .parent()
+    .unwrap()
+    .parent()
+    .unwrap()
+    .parent()
+    .unwrap();
+  let download_dir = target_dir.join("gn_ninja_binaries");
+  let d = download_dir.join("gn_ninja_binaries").join(platform());
   let gn = d.join("gn");
   let ninja = d.join("ninja");
   #[cfg(windows)]
@@ -121,7 +132,7 @@ fn download_gn_ninja_binaries() {
     let status = Command::new("python")
       .arg("./tools/gn_ninja_binaries.py")
       .arg("--dir")
-      .arg(&out_dir)
+      .arg(&download_dir)
       .status()
       .expect("gn_ninja_binaries.py download failed");
     assert!(status.success());
diff --git a/tools/gn_ninja_binaries.py b/tools/gn_ninja_binaries.py
index 7aa84d24..0047ea9b 100755
--- a/tools/gn_ninja_binaries.py
+++ b/tools/gn_ninja_binaries.py
@@ -87,7 +87,7 @@ def EnsureDirExists(path):
         os.makedirs(path)
 
 
-def DownloadAndUnpack(url, output_dir, path_prefixes=None):
+def DownloadAndUnpack(url, output_dir):
     """Download an archive from url and extract into output_dir. If path_prefixes
      is not None, only extract files whose paths within the archive start with
      any prefix in path_prefixes."""
@@ -96,20 +96,14 @@ def DownloadAndUnpack(url, output_dir, path_prefixes=None):
         f.seek(0)
         EnsureDirExists(output_dir)
         t = tarfile.open(mode='r:gz', fileobj=f)
-        members = None
-        if path_prefixes is not None:
-            members = [
-                m for m in t.getmembers() if any(
-                    m.name.startswith(p) for p in path_prefixes)
-            ]
-        t.extractall(path=output_dir, members=members)
+        t.extractall(path=output_dir)
 
 
 def Update():
     if os.path.exists(DIR):
         RmTree(DIR)
     try:
-        DownloadAndUnpack(URL, DIR, None)
+        DownloadAndUnpack(URL, DIR)
     except URLError:
         print('Failed to download prebuilt ninja/gn binaries %s' % URL)
         print('Exiting.')