diff --git a/tests/test_stage.py b/tests/test_stage.py
new file mode 100644
index 000000000..fe4f0d046
--- /dev/null
+++ b/tests/test_stage.py
@@ -0,0 +1,63 @@
+from dvc.output import Output
+from dvc.stage import Stage, StageFileFormatError
+
+from tests.basic_env import TestDvc
+
+
+class TestSchema(TestDvc):
+    def _validate_fail(self, d):
+        with self.assertRaises(StageFileFormatError):
+            Stage.validate(d)
+
+
+class TestSchemaCmd(TestSchema):
+    def test_cmd_object(self):
+        d = {Stage.PARAM_CMD: {}}
+        self._validate_fail(d)
+
+    def test_cmd_none(self):
+        d = {Stage.PARAM_CMD: None}
+        Stage.validate(d)
+
+    def test_no_cmd(self):
+        d = {}
+        Stage.validate(d)
+
+    def test_cmd_str(self):
+        d = {Stage.PARAM_CMD: 'cmd'}
+        Stage.validate(d)
+
+
+class TestSchemaDepsOuts(TestSchema):
+    def test_object(self):
+        d = {Stage.PARAM_DEPS: {}}
+        self._validate_fail(d)
+
+        d = {Stage.PARAM_OUTS: {}}
+        self._validate_fail(d)
+
+    def test_none(self):
+        d = {Stage.PARAM_DEPS: None}
+        Stage.validate(d)
+
+        d = {Stage.PARAM_OUTS: None}
+        Stage.validate(d)
+
+    def test_empty_list(self):
+        d = {Stage.PARAM_DEPS: []}
+        Stage.validate(d)
+
+        d = {Stage.PARAM_OUTS: []}
+        Stage.validate(d)
+
+    def test_list(self):
+        l = [{Output.PARAM_PATH: 'foo', Output.PARAM_MD5: '123'},
+             {Output.PARAM_PATH: 'bar', Output.PARAM_MD5: None},
+             {Output.PARAM_PATH: 'baz'}]
+        d = {Stage.PARAM_DEPS: l}
+        Stage.validate(d)
+
+        l[0][Output.PARAM_CACHE] = True
+        l[1][Output.PARAM_CACHE] = False
+        d = {Stage.PARAM_OUTS: l}
+        Stage.validate(d)