diff --git a/dvc/api.py b/dvc/api.py
index 7bde1b0be..013eb0a51 100644
--- a/dvc/api.py
+++ b/dvc/api.py
@@ -9,12 +9,13 @@ try:
 except ImportError:
     from contextlib import GeneratorContextManager as GCM
 
+from dvc.utils.compat import urlparse, builtin_str
+
 import ruamel.yaml
 from voluptuous import Schema, Required, Invalid
 
-from dvc.utils.compat import urlparse, builtin_str
 from dvc.repo import Repo
-from dvc.exceptions import SummonError, FileMissingError
+from dvc.exceptions import DvcException, FileMissingError
 from dvc.external_repo import external_repo
 
 
@@ -36,6 +37,10 @@ SUMMON_SCHEMA = Schema(
 )
 
 
+class SummonError(DvcException):
+    pass
+
+
 def get_url(path, repo=None, rev=None, remote=None):
     """Returns an url of a resource specified by path in repo"""
     with _make_repo(repo, rev=rev) as _repo:
@@ -109,7 +114,7 @@ def summon(name, repo=None, rev=None, summon_file="dvcsummon.yaml", args=None):
                 cause=exc.cause,
             )
 
-        _pull_dependencies(_repo, info.get("deps"))
+        _pull_dependencies(_repo, info.get("deps", []))
 
         _args = copy.deepcopy(info.get("args", {}))
         _args.update(args or {})
diff --git a/dvc/exceptions.py b/dvc/exceptions.py
index 18ec671f2..7151e2e2f 100644
--- a/dvc/exceptions.py
+++ b/dvc/exceptions.py
@@ -353,7 +353,3 @@ class PathMissingError(DvcException):
             " neighther as an output nor a git-handled file."
         )
         super(PathMissingError, self).__init__(msg.format(path, repo))
-
-
-class SummonError(DvcException):
-    pass
diff --git a/tests/func/test_api.py b/tests/func/test_api.py
index bff3abe51..ba05e9a9c 100644
--- a/tests/func/test_api.py
+++ b/tests/func/test_api.py
@@ -8,12 +8,12 @@ import ruamel.yaml
 import pytest
 
 from dvc import api
+from dvc.api import SummonError
 from dvc.exceptions import FileMissingError
 from dvc.main import main
 from dvc.path_info import URLInfo
 from dvc.remote.config import RemoteConfig
 from dvc.utils.compat import fspath
-from dvc.exceptions import SummonError
 from tests.remotes import Azure, GCP, HDFS, Local, OSS, S3, SSH
 
 
@@ -148,27 +148,21 @@ def test_summon(tmp_dir, erepo_dir, dvc, monkeypatch):
         ]
     }
 
-    different_objects = copy.deepcopy(objects)
-    different_objects["objects"][0]["summon"]["args"]["x"] = 100
+    other_objects = copy.deepcopy(objects)
+    other_objects["objects"][0]["summon"]["args"]["x"] = 100
 
     dup_objects = copy.deepcopy(objects)
     dup_objects["objects"] *= 2
 
-    dvcsummon_yaml = ruamel.yaml.dump(objects)
-    different_yaml = ruamel.yaml.dump(different_objects)
-    dup_yaml = ruamel.yaml.dump(dup_objects)
-    invalid_yaml = ruamel.yaml.dump({"name": "sum"})
-    not_yaml = "a: - this is not a valid YAML file"
-
     with monkeypatch.context() as m:
         m.chdir(fspath(erepo_dir))
 
         erepo_dir.dvc_gen("number", "100", commit="Add number.dvc")
-        erepo_dir.scm_gen("dvcsummon.yaml", dvcsummon_yaml)
-        erepo_dir.scm_gen("different.yaml", different_yaml)
-        erepo_dir.scm_gen("dup.yaml", dup_yaml)
-        erepo_dir.scm_gen("invalid.yaml", invalid_yaml)
-        erepo_dir.scm_gen("not_yaml.yaml", not_yaml)
+        erepo_dir.scm_gen("dvcsummon.yaml", ruamel.yaml.dump(objects))
+        erepo_dir.scm_gen("other.yaml", ruamel.yaml.dump(other_objects))
+        erepo_dir.scm_gen("dup.yaml", ruamel.yaml.dump(dup_objects))
+        erepo_dir.scm_gen("invalid.yaml", ruamel.yaml.dump({"name": "sum"}))
+        erepo_dir.scm_gen("not_yaml.yaml", "a: - this is not a YAML file")
         erepo_dir.scm_gen(
             "calculator.py",
             "def add_to_num(x): return x + int(open('number').read())",
@@ -179,9 +173,7 @@ def test_summon(tmp_dir, erepo_dir, dvc, monkeypatch):
 
     assert api.summon("sum", repo=repo_url) == 101
     assert api.summon("sum", repo=repo_url, args={"x": 2}) == 102
-    assert (
-        api.summon("sum", repo=repo_url, summon_file="different.yaml") == 200
-    )
+    assert api.summon("sum", repo=repo_url, summon_file="other.yaml") == 200
 
     try:
         api.summon("sum", repo=repo_url, summon_file="missing.yaml")