diff --git a/cli/test/generate_test_db/main.py b/cli/test/generate_test_db/main.py
index d4049d2..2a5328d 100644
--- a/cli/test/generate_test_db/main.py
+++ b/cli/test/generate_test_db/main.py
@@ -109,7 +109,7 @@ def _generate_test_db():
                     add_part_student(student, be_2_ws_part)
 
         program_groups = {program: [] for program in programs}
-        for _semester, program_part_students in semester_program_part_students.items():
+        for program_part_students in semester_program_part_students.values():
             for program, part_students in program_part_students.items():
                 if len(part_students) % 2 == 1:
                     # Add the first 3 students into a special group for an uneven number of students
diff --git a/pyproject.toml b/pyproject.toml
index f0d954d..620dc40 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -47,8 +47,19 @@ select = [
   "ERA",
   "PL",
   "NPY",
+  "PERF",
+]
+ignore = [
+  "E5",
+  "S3",
+  "S6",
+  "RET504",
+  "PLR0912",
+  "PLR0915",
+  "PLW2901",
+  "PLR2004",
+  "PERF203",
 ]
-ignore = ["E5", "S3", "S6", "RET504", "PLR0912", "PLR0915", "PLW2901", "PLR2004"]
 line-length = 120
 
 [tool.ruff.per-file-ignores]