diff --git a/testing/chromium/build b/testing/chromium/build
index 63e81b2b..2c4b84b9 100755
--- a/testing/chromium/build
+++ b/testing/chromium/build
@@ -5,7 +5,7 @@ git clone --depth 1 \
 
 export PATH="$PATH:$PWD/depot_tools"
 
-PYTHONDONTWRITEBYTECODE=1 python2 ./gn.py gen out/Default \
+PYTHONDONTWRITEBYTECODE=1 python2 "$PWD/depot_tools/gn.py" gen out/Default \
     --args='target_cpu="x64" is_debug=false use_jumbo_build=true enable_nacl=false symbol_level=0 blink_symbol_level=0 enable_nacl_nonsfi=false use_gtk3=true use_gold=false treat_warnings_as_errors=false fatal_linker_warnings=false use_sysroot=false use_cups=false rtc_use_x11=true use_dbus=false safe_browsing_mode=0 use_pulseaudio=false use_use_gconf=false use_gio=false use_gnome_keyring=false use_kerberos=false'
 
 ninja -C out/Release chrome chromedriver