diff --git a/hyperglass/frontend/__init__.py b/hyperglass/frontend/__init__.py
index bbd7acea..0186c2e6 100644
--- a/hyperglass/frontend/__init__.py
+++ b/hyperglass/frontend/__init__.py
@@ -273,6 +273,8 @@ async def build_frontend(  # noqa: C901
     # Create temporary file. json file extension is added for easy
     # webpack JSON parsing.
     dot_env_file = Path(__file__).parent.parent / "ui" / ".env"
+    build_id_dot_env_dir = app_path / "static"
+    build_id_dot_env_file = build_id_dot_env_dir / ".env"
     env_config = {}
 
     ui_config_file = Path(__file__).parent.parent / "ui" / "hyperglass.json"
@@ -320,7 +322,7 @@ async def build_frontend(  # noqa: C901
         write_favicon_formats(favicons.formats())
 
     build_data = {
-        "params": params.export_dict(),
+        "params": sorted(params.export_dict()),
         "version": __version__,
         "package_json": package_json,
     }
@@ -333,8 +335,10 @@ async def build_frontend(  # noqa: C901
 
     # Read hard-coded environment file from last build. If build ID
     # matches this build's ID, don't run a new build.
-    if dot_env_file.exists() and not force:
-        env_data = dotenv_to_dict(dot_env_file)
+    if not build_id_dot_env_dir.exists():
+        build_id_dot_env_dir.mkdir()
+    if build_id_dot_env_file.exists() and not force:
+        env_data = dotenv_to_dict(build_id_dot_env_file)
         env_build_id = env_data.get("HYPERGLASS_BUILD_ID", "None")
         log.bind(id=env_build_id).debug("Previous build detected")
 
@@ -342,8 +346,6 @@ async def build_frontend(  # noqa: C901
             log.debug("UI parameters unchanged since last build, skipping UI build...")
             return True
 
-    env_config.update({"HYPERGLASS_BUILD_ID": build_id})
-
     dot_env_file.write_text("\n".join(f"{k}={v}" for k, v in env_config.items()))
     log.bind(path=str(dot_env_file)).debug("Wrote UI environment file")
 
@@ -375,4 +377,7 @@ async def build_frontend(  # noqa: C901
         params.web.theme.colors.black,
     )
 
+    build_id_dot_env_file.write_text(f"HYPERGLASS_BUILD_ID={build_id}")
+    log.bind(path=str(build_id_dot_env_file)).debug("Wrote UI build environment file")
+
     return True