diff --git a/bauh/api/abstract/controller.py b/bauh/api/abstract/controller.py
index dde6334e..dd3e3e5e 100644
--- a/bauh/api/abstract/controller.py
+++ b/bauh/api/abstract/controller.py
@@ -360,8 +360,7 @@ class SoftwareManager(ABC):
         """
         pass
 
-    @abstractmethod
-    def list_suggestions(self, limit: int, filter_installed: bool) -> List[PackageSuggestion]:
+    def list_suggestions(self, limit: int, filter_installed: bool) -> Optional[List[PackageSuggestion]]:
         """
         :param limit: max suggestions to be returned. If limit < 0, it should not be considered
         :param filter_installed: if the installed suggestions should not be retrieved
diff --git a/bauh/gems/appimage/controller.py b/bauh/gems/appimage/controller.py
index e2ec91c6..bf1775ea 100644
--- a/bauh/gems/appimage/controller.py
+++ b/bauh/gems/appimage/controller.py
@@ -767,7 +767,7 @@ class AppImageManager(SoftwareManager, SettingsController):
         if not dbfiles or len({f for f in (DATABASE_APPS_FILE, DATABASE_RELEASES_FILE) if f in dbfiles}) != 2:
             return [self.i18n['appimage.warning.missing_db_files'].format(appimage=bold('AppImage'))]
 
-    def list_suggestions(self, limit: int, filter_installed: bool) -> List[PackageSuggestion]:
+    def list_suggestions(self, limit: int, filter_installed: bool) -> Optional[List[PackageSuggestion]]:
         res = []
 
         connection = self._get_db_connection(DATABASE_APPS_FILE)
diff --git a/bauh/gems/arch/controller.py b/bauh/gems/arch/controller.py
index e0cacde7..abe3a6d2 100644
--- a/bauh/gems/arch/controller.py
+++ b/bauh/gems/arch/controller.py
@@ -2797,7 +2797,7 @@ class ArchManager(SoftwareManager, SettingsController):
         if not git.is_installed():
             return [self.i18n['arch.warning.aur_missing_dep'].format(bold('git'))]
 
-    def list_suggestions(self, limit: int, filter_installed: bool) -> List[PackageSuggestion]:
+    def list_suggestions(self, limit: int, filter_installed: bool) -> Optional[List[PackageSuggestion]]:
         self.logger.info("Downloading suggestions file {}".format(SUGGESTIONS_FILE))
         file = self.http_client.get(SUGGESTIONS_FILE)
 
diff --git a/bauh/gems/debian/controller.py b/bauh/gems/debian/controller.py
index 183e4995..9abaa7f9 100644
--- a/bauh/gems/debian/controller.py
+++ b/bauh/gems/debian/controller.py
@@ -521,7 +521,7 @@ class DebianPackageManager(SoftwareManager, SettingsController):
         if suggestions:
             output.update(suggestions)
 
-    def list_suggestions(self, limit: int, filter_installed: bool) -> List[PackageSuggestion]:
+    def list_suggestions(self, limit: int, filter_installed: bool) -> Optional[List[PackageSuggestion]]:
         name_priority = dict()
 
         fill_suggestions = Thread(target=self._fill_suggestions, args=(name_priority,))
diff --git a/bauh/gems/flatpak/controller.py b/bauh/gems/flatpak/controller.py
index 38586355..0921ba48 100644
--- a/bauh/gems/flatpak/controller.py
+++ b/bauh/gems/flatpak/controller.py
@@ -537,7 +537,7 @@ class FlatpakManager(SoftwareManager, SettingsController):
     def list_warnings(self, internet_available: bool) -> Optional[List[str]]:
         pass
 
-    def list_suggestions(self, limit: int, filter_installed: bool) -> List[PackageSuggestion]:
+    def list_suggestions(self, limit: int, filter_installed: bool) -> Optional[List[PackageSuggestion]]:
         cli_version = flatpak.get_version()
         res = []
 
diff --git a/bauh/gems/snap/controller.py b/bauh/gems/snap/controller.py
index 29975889..df7d9236 100644
--- a/bauh/gems/snap/controller.py
+++ b/bauh/gems/snap/controller.py
@@ -361,7 +361,7 @@ class SnapManager(SoftwareManager, SettingsController):
         app.status = PackageStatus.READY
         return app
 
-    def list_suggestions(self, limit: int, filter_installed: bool) -> List[PackageSuggestion]:
+    def list_suggestions(self, limit: int, filter_installed: bool) -> Optional[List[PackageSuggestion]]:
         res = []
 
         if snapd.is_running():
diff --git a/bauh/gems/web/controller.py b/bauh/gems/web/controller.py
index 4aed86cd..9018acde 100644
--- a/bauh/gems/web/controller.py
+++ b/bauh/gems/web/controller.py
@@ -1023,7 +1023,7 @@ class WebApplicationManager(SoftwareManager, SettingsController):
     def _fill_config_async(self, output: dict):
         output.update(self.configman.get_config())
 
-    def list_suggestions(self, limit: int, filter_installed: bool) -> List[PackageSuggestion]:
+    def list_suggestions(self, limit: int, filter_installed: bool) -> Optional[List[PackageSuggestion]]:
         web_config = {}
 
         thread_config = Thread(target=self._fill_config_async, args=(web_config,))