diff --git a/tests/conftest.py b/tests/conftest.py
index 65d68268..86135ecd 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -336,6 +336,7 @@ def schema_simp(connection_test, prefix):
     schema(schema_simple.B)
     schema(schema_simple.L)
     schema(schema_simple.D)
+    schema(schema_simple.N)
     schema(schema_simple.E)
     schema(schema_simple.F)
     schema(schema_simple.F)
diff --git a/tests/schema_simple.py b/tests/schema_simple.py
index 9e3113c9..c563abea 100644
--- a/tests/schema_simple.py
+++ b/tests/schema_simple.py
@@ -92,7 +92,33 @@ def _make_tuples(self, key):
         # make reference to a random tuple from L
         random.seed(str(key))
         lookup = list(L().fetch("KEY"))
-        self.insert(dict(key, id_d=i, **random.choice(lookup)) for i in range(4))
+        self.insert(dict(key, id_d=i, **random.choice(lookup))
+                    for i in range(4))
+
+
+class N(dj.Computed):
+    definition = """
+    # test for three part make function
+    -> A
+    id_d :int
+    ---
+    -> L
+    """
+
+    def make_fetch(self, key):
+        # make reference to a random tuple from L
+        lookup = list(L().fetch("KEY"))
+        inputs = key, lookup
+        return inputs
+
+    def make_compute(self, inputs):
+        key, lookup = inputs
+        random.seed(str(key))
+        values = [dict(key, id_d=i, **random.choice(lookup)) for i in range(4)]
+        return values
+
+    def make_insert(self, values):
+        self.insert(values)
 
 
 class E(dj.Computed):
diff --git a/tests/test_autopopulate.py b/tests/test_autopopulate.py
index d1f0726e..d0e9dad7 100644
--- a/tests/test_autopopulate.py
+++ b/tests/test_autopopulate.py
@@ -1,16 +1,15 @@
 import pytest
 from datajoint import DataJointError
 import datajoint as dj
-import pymysql
-from . import schema
 
 
-def test_populate(trial, subject, experiment, ephys, channel):
+def test_populate(schema_any, trial, subject, experiment, ephys, channel):
     # test simple populate
     assert subject, "root tables are empty"
     assert not experiment, "table already filled?"
     experiment.populate()
-    assert len(experiment) == len(subject) * experiment.fake_experiments_per_subject
+    assert len(experiment) == len(subject) * \
+        experiment.fake_experiments_per_subject
 
     # test restricted populate
     assert not trial, "table already filled?"
@@ -31,7 +30,7 @@ def test_populate(trial, subject, experiment, ephys, channel):
     assert channel
 
 
-def test_populate_with_success_count(subject, experiment, trial):
+def test_populate_with_success_count(schema_any, subject, experiment, trial):
     # test simple populate
     assert subject, "root tables are empty"
     assert not experiment, "table already filled?"
@@ -62,10 +61,11 @@ def test_populate_exclude_error_and_ignore_jobs(schema_any, subject, experiment)
             schema_any.jobs.error(experiment.table_name, key, "")
 
     experiment.populate(reserve_jobs=True)
-    assert len(experiment.key_source & experiment) == len(experiment.key_source) - 2
+    assert len(experiment.key_source & experiment) == len(
+        experiment.key_source) - 2
 
 
-def test_allow_direct_insert(subject, experiment):
+def test_allow_direct_insert(schema_any, subject, experiment):
     assert subject, "root tables are empty"
     key = subject.fetch("KEY", limit=1)[0]
     key["experiment_id"] = 1000
@@ -74,14 +74,15 @@ def test_allow_direct_insert(subject, experiment):
 
 
 @pytest.mark.parametrize("processes", [None, 2])
-def test_multi_processing(subject, experiment, processes):
+def test_multi_processing(schema_any, subject, experiment, processes):
     assert subject, "root tables are empty"
     assert not experiment, "table already filled?"
     experiment.populate(processes=None)
-    assert len(experiment) == len(subject) * experiment.fake_experiments_per_subject
+    assert len(experiment) == len(subject) * \
+        experiment.fake_experiments_per_subject
 
 
-def test_allow_insert(subject, experiment):
+def test_allow_insert(schema_any, subject, experiment):
     assert subject, "root tables are empty"
     key = subject.fetch("KEY")[0]
     key["experiment_id"] = 1001