diff --git a/frontools/cli.py b/frontools/cli.py
index 474409a..2cb87db 100644
--- a/frontools/cli.py
+++ b/frontools/cli.py
@@ -39,6 +39,7 @@ def _async_command(function: Any) -> Any:
     help="Source to use (configured in config file)",
 )
 @option("--no-cache", type=bool, help="Disable caching", count=True)
+@option("-u", "--update-index", type=bool, help="Reload cached theme index", count=True)
 @option(
     "--include-urls",
     type=str,
@@ -71,6 +72,7 @@ async def main(
     config_file: Optional[Path],
     source: str,
     no_cache: bool,
+    update_index: bool,
     include_urls: list[str],
     exclude_urls: list[str],
     include_tags: list[str],
@@ -79,6 +81,7 @@ async def main(
     """Utilities for EO frontend development."""
     ctx.obj = await Config.load(
         config_file,
+        update_index,
         source,
         not no_cache,
         include_urls,
diff --git a/frontools/config.py b/frontools/config.py
index 4630d54..e6c4ec3 100644
--- a/frontools/config.py
+++ b/frontools/config.py
@@ -47,7 +47,7 @@ class Config:
         )
 
     @staticmethod
-    async def load(config_path: Optional[Path], *args: Any, **kwargs: Any) -> "Config":
+    async def load(config_path: Optional[Path], update_index: bool, *args: Any, **kwargs: Any) -> "Config":
         """Load config from the given path"""
         config = Config(*args, **kwargs)
 
@@ -71,7 +71,7 @@ class Config:
 
             config_loader = getattr(config_module, "CONFIG")
             await config_loader(config)
-            await config._theme_index.load()
+            await config._theme_index.load(update_index)
 
         return config
 
diff --git a/frontools/theme_index.py b/frontools/theme_index.py
index 16539c8..d1cbc2d 100644
--- a/frontools/theme_index.py
+++ b/frontools/theme_index.py
@@ -40,16 +40,15 @@ class ThemeIndex:
 
     def add_urls(self, *urls: UrlEntry) -> None:
         """Add an url for a theme"""
-        for url in urls:
-            self._inputs.urls.append(url)
+        self._inputs.urls.extend(urls)
 
     def add_yaml(self, yaml_path: Path) -> None:
         """Load a yaml file containing dictionnary of urls to add as themes."""
         self._inputs.yaml_files.append(yaml_path)
 
-    async def load(self) -> None:
+    async def load(self, update_cache: bool) -> None:
         index_cache = xdg_cache_home() / "frontools" / "index-cache.yaml"
-        if index_cache.is_file():
+        if index_cache.is_file() and not update_cache:
             _Inputs.yaml_files.append(index_cache)
         else:
             await self._load_urls_without_theme()