diff --git a/fdroidserver/metadata.py b/fdroidserver/metadata.py
index d69fb6f1..15f5779d 100644
--- a/fdroidserver/metadata.py
+++ b/fdroidserver/metadata.py
@@ -203,7 +203,7 @@ fieldtypes = {
     'Categories': TYPE_LIST,
     'AntiFeatures': TYPE_LIST,
     'AllowedAPKSigningKeys': TYPE_LIST,
-    'Build': TYPE_BUILD,
+    'Builds': TYPE_BUILD,
 }
 
 
diff --git a/tests/metadata.TestCase b/tests/metadata.TestCase
index 07d8edcf..607dc92f 100755
--- a/tests/metadata.TestCase
+++ b/tests/metadata.TestCase
@@ -46,6 +46,14 @@ class MetadataTest(unittest.TestCase):
         # TODO: Python3.6: Accepts a path-like object.
         os.chdir(str(self.basedir))
 
+    def test_fieldtypes_key_exist(self):
+        for k in fdroidserver.metadata.fieldtypes.keys():
+            self.assertTrue(k in fdroidserver.metadata.yaml_app_fields)
+
+    def test_build_flagtypes_key_exist(self):
+        for k in fdroidserver.metadata.flagtypes.keys():
+            self.assertTrue(k in fdroidserver.metadata.build_flags)
+
     def test_FieldValidator_BitcoinAddress(self):
         validator = None
         for vali in fdroidserver.metadata.valuetypes:
diff --git a/tests/update.TestCase b/tests/update.TestCase
index 7e7f8583..7c669760 100755
--- a/tests/update.TestCase
+++ b/tests/update.TestCase
@@ -1424,7 +1424,7 @@ class UpdateTest(unittest.TestCase):
                         'AutoUpdateMode': '',
                         'Binaries': '',
                         'Bitcoin': '',
-                        'Builds': '',
+                        'Builds': None,
                         'Changelog': '',
                         'CurrentVersion': '',
                         'CurrentVersionCode': '',