diff --git a/qutebrowser/api/interceptor.py b/qutebrowser/api/interceptor.py
index afd23d067..a40635fca 100644
--- a/qutebrowser/api/interceptor.py
+++ b/qutebrowser/api/interceptor.py
@@ -27,6 +27,7 @@ from qutebrowser.extensions.interceptors import Request
 def register(interceptor: interceptors.InterceptorType) -> None:
     """Register a request interceptor.
 
-    Whenever a request happens, the interceptor gets called with a Request object.
+    Whenever a request happens, the interceptor gets called with a Request
+    object.
     """
     interceptors.register(interceptor)
diff --git a/qutebrowser/components/adblock.py b/qutebrowser/components/adblock.py
index bccb53532..9baa12d7c 100644
--- a/qutebrowser/components/adblock.py
+++ b/qutebrowser/components/adblock.py
@@ -109,7 +109,7 @@ class HostBlocker:
         self._config_hosts_file = str(config_dir / 'blocked-hosts')
 
     def _is_blocked(self, request_url: QUrl,
-                    first_party_url: QUrl = None) -> None:
+                    first_party_url: QUrl = None) -> bool:
         """Check whether the given request is blocked."""
         if first_party_url is not None and not first_party_url.isValid():
             first_party_url = None
diff --git a/qutebrowser/extensions/loader.py b/qutebrowser/extensions/loader.py
index d7a106344..1383adfef 100644
--- a/qutebrowser/extensions/loader.py
+++ b/qutebrowser/extensions/loader.py
@@ -87,7 +87,7 @@ def add_module_info(module: types.ModuleType) -> ModuleInfo:
     return module.__qute_module_info  # type: ignore
 
 
-def load_components(*, skip_hooks=False) -> None:
+def load_components(*, skip_hooks: bool = False) -> None:
     """Load everything from qutebrowser.components."""
     for info in walk_components():
         _load_component(info, skip_hooks=skip_hooks)
@@ -143,7 +143,7 @@ def _get_init_context() -> InitContext:
 
 
 def _load_component(info: ExtensionInfo, *,
-                    skip_hooks=False) -> types.ModuleType:
+                    skip_hooks: bool = False) -> types.ModuleType:
     """Load the given extension and run its init hook (if any).
 
     Args:
diff --git a/tests/unit/extensions/test_loader.py b/tests/unit/extensions/test_loader.py
index 0a7edc9d3..5265c7cdf 100644
--- a/tests/unit/extensions/test_loader.py
+++ b/tests/unit/extensions/test_loader.py
@@ -75,6 +75,7 @@ def test_get_init_context(data_tmpdir, config_tmpdir, fake_args):
 
 
 def test_add_module_info():
+    # pylint: disable=no-member
     mod = types.ModuleType('testmodule')
     info1 = loader.add_module_info(mod)
     assert mod.__qute_module_info is info1