diff --git a/python/setup.py b/python/setup.py
index b52a4d310d0c..b99544f1f3ea 100644
--- a/python/setup.py
+++ b/python/setup.py
@@ -127,7 +127,7 @@ def is_offline_build() -> bool:
 
     Note that this flag isn't tested by the CI and does not provide any guarantees.
     """
-    return os.environ.get("TRITON_OFFLINE_BUILD", "") != ""
+    return check_env_flag("TRITON_OFFLINE_BUILD", "")
 
 
 # --- third party packages -----
@@ -450,6 +450,10 @@ def build_extension(self, ext):
         else:
             cmake_args += ["-DTRITON_BUILD_PROTON=OFF"]
 
+        if is_offline_build():
+            # unit test builds fetch googletests from GitHub
+            cmake_args += ["-DTRITON_BUILD_UT=OFF"]
+
         cmake_args_append = os.getenv("TRITON_APPEND_CMAKE_ARGS")
         if cmake_args_append is not None:
             cmake_args += shlex.split(cmake_args_append)