diff --git a/util/icat_db_generator.py b/util/icat_db_generator.py
index 15b41c2d..3f95f676 100644
--- a/util/icat_db_generator.py
+++ b/util/icat_db_generator.py
@@ -34,9 +34,6 @@
 faker = Faker()
 Faker.seed(SEED)
 
-pid_faker = Faker()
-pid_faker.seed_instance(SEED)
-
 
 engine = create_engine(
     config.get_config_value(APIConfigOptions.DB_URL),
@@ -426,6 +423,8 @@ def generate_user_groups(i):
 class StudyGenerator(Generator):
     tier = 3
     amount = UserGenerator.amount
+    pid_faker = Faker()
+    pid_faker.seed_instance(SEED)
 
     def generate(self):
         for i in range(1, self.amount):
@@ -437,7 +436,7 @@ def generate_studies(i):
         apply_common_attributes(study, i)
         study.startDate = get_start_date(i)
         study.status = faker.random_int(0, 1)
-        study.pid = pid_faker.isbn10(separator="-")
+        study.pid = StudyGenerator.pid_faker.isbn10(separator="-")
         study.userID = i
         post_entity(study)