diff --git a/ruff.toml b/ruff.toml
index d5892e4..6567cdb 100644
--- a/ruff.toml
+++ b/ruff.toml
@@ -32,7 +32,6 @@ lint.extend-ignore = [
     "S320", # OK, we're using defusedxml
 
     # Fix these (if possible / reasonable)
-    "B024", # `...` is an abstract base class, but it has no abstract methods
     "B027", # `...` is an empty method in an abstract base class, but has no abstract decorator
     "B028", # No explicit `...` keyword argument found
     "BLE001", # Do not catch blind exception
@@ -56,7 +55,6 @@ lint.extend-ignore = [
     "N806", # Variable in function should be lowercase
     #
     "PD011", # Use `.to_numpy()` instead of `.values`
-    "PERF203", # `try`-`except` within a loop incurs performance overhead
     "PLC0206", # Extracting value from dictionary without calling `.items()`
     "PLC0415", # `import` should be at the top-level of a file
     "PLC1901", # `x == ""` can be simplified to `not x` as an empty string is falsey
diff --git a/src/abilian/core/models/attachment.py b/src/abilian/core/models/attachment.py
index e2f44b9..fb5c6b1 100644
--- a/src/abilian/core/models/attachment.py
+++ b/src/abilian/core/models/attachment.py
@@ -19,8 +19,8 @@
 ATTRIBUTE = "__attachments__"
 
 
-class SupportsAttachment(abc.ABC):
-    pass
+class SupportsAttachment(abc.ABC):  # noqa: B024
+    """Mixin for entities that can have attachments."""
 
 
 def register(cls):
diff --git a/src/abilian/web/assets/filters.py b/src/abilian/web/assets/filters.py
index 582153d..25ef937 100644
--- a/src/abilian/web/assets/filters.py
+++ b/src/abilian/web/assets/filters.py
@@ -355,7 +355,7 @@ def output(self, _in, out, **kw):
 
         name = smap_path.name
         out.write(f"//# sourceMappingURL={name!s}")
-        self.fix_source_map_urls(str(smap_path))
+        self.fix_source_map_urls(smap_path)
 
     def fix_url(self, cur_path, src_path):
         possible_paths = [p for p in self.ctx.url_mapping if src_path.startswith(p)]
@@ -374,8 +374,8 @@ def fix_url(self, cur_path, src_path):
         path = possible_paths[0]
         return self.ctx.url_mapping[path] + src_path[len(path) :]
 
-    def fix_source_map_urls(self, filename):
-        with open(filename) as f:
+    def fix_source_map_urls(self, file_path: Path):
+        with file_path.open() as f:
             data = json.load(f)
 
         for idx, path in enumerate(data["sources"]):
@@ -385,7 +385,7 @@ def fix_source_map_urls(self, filename):
 
             data["sources"][idx] = self.fix_url(self.ctx.directory, path)
 
-        with open(filename, "w") as f:
+        with file_path.open("w") as f:
             json.dump(data, f)