diff --git a/accountant/views/accounts.py b/accountant/views/accounts.py
index 44eddbb..32de41c 100644
--- a/accountant/views/accounts.py
+++ b/accountant/views/accounts.py
@@ -213,8 +213,8 @@ class AccountResource(Resource):
             ns.abort(404, 'Account with id %d not found.' % account_id)
 
         # SQLAlchemy objects ignore __dict__.update() with merge.
-        for k, v in data.items():
-            setattr(account, k, v)
+        for key, value in data.items():
+            setattr(account, key, value)
 
         db.session.merge(account)  # pylint: disable=no-member
 
diff --git a/accountant/views/operations.py b/accountant/views/operations.py
index d9c233c..cc0cc5f 100644
--- a/accountant/views/operations.py
+++ b/accountant/views/operations.py
@@ -194,8 +194,8 @@ class OperationResource(Resource):
         # FIXME check account_id consistency.
 
         # SQLAlchemy objects ignore __dict__.update() with merge.
-        for k, v in data.items():
-            setattr(operation, k, v)
+        for key, value in data.items():
+            setattr(operation, key, value)
 
         db.session.merge(operation)  # pylint: disable=no-member
 
diff --git a/accountant/views/scheduled_operations.py b/accountant/views/scheduled_operations.py
index c393495..b73c992 100644
--- a/accountant/views/scheduled_operations.py
+++ b/accountant/views/scheduled_operations.py
@@ -171,8 +171,8 @@ class ScheduledOperationResource(Resource):
         # FIXME check account_id consistency.
 
         # SQLAlchemy objects ignore __dict__.update() with merge.
-        for k, v in data.items():
-            setattr(scheduled_operation, k, v)
+        for key, value in data.items():
+            setattr(scheduled_operation, key, value)
 
         db.session.merge(scheduled_operation)  # pylint: disable=no-member