diff --git a/libcove/lib/common.py b/libcove/lib/common.py
index 5940fc3..342cb8d 100644
--- a/libcove/lib/common.py
+++ b/libcove/lib/common.py
@@ -18,13 +18,29 @@
 from cached_property import cached_property
 from flattentool import unflatten
 from jsonschema import FormatChecker, RefResolver
-from jsonschema._utils import extras_msg, find_additional_properties, uniq
+from jsonschema._utils import (
+    ensure_list,
+    extras_msg,
+    find_additional_properties,
+    types_msg,
+    uniq,
+)
 from jsonschema.exceptions import UndefinedTypeCheck, ValidationError
 
 from .exceptions import cove_spreadsheet_conversion_error
 from .tools import decimal_default, get_request
 
 
+def type_validator(validator, types, instance, schema):
+    types = ensure_list(types)
+
+    for type in types:
+        if validator.is_type(instance, type):
+            break
+    else:
+        yield ValidationError(types_msg(instance, types))
+
+
 class TypeChecker:
     def is_type(self, instance, type):
         if type == "string":
@@ -52,7 +68,9 @@ def is_type(self, instance, type):
 # Otherwise we could cause conflicts with other software in the same process.
 validator = jsonschema.validators.extend(
     jsonschema.validators.Draft4Validator,
-    validators={},
+    validators={
+        "type": type_validator,
+    },
     type_checker=TypeChecker(),
 )
 
diff --git a/tests/lib/test_common.py b/tests/lib/test_common.py
index 633b29c..0c19c52 100644
--- a/tests/lib/test_common.py
+++ b/tests/lib/test_common.py
@@ -765,7 +765,7 @@ class DummySchemaObj:
 
         def get_pkg_schema_obj(self):
             return {
-                "type": "array",
+                "type": ["array"],
                 "minItems": 2,
             }