diff --git a/private/attributes b/private/attributes
index 3d18d71..cf1c307 100644
--- a/private/attributes
+++ b/private/attributes
@@ -4,3 +4,8 @@
 # to exempt them from recent mls changes. It must not be applied
 # to any domain on newer system or vendor image.
 attribute mlsvendorcompat;
+
+# Attributes for property types having both system_property_type
+# and vendor_property_type. Such types are ill-formed because
+# property owner attributes must be exclusive.
+attribute system_and_vendor_property_type;
diff --git a/private/property.te b/private/property.te
index 480d3e3..1163a3c 100644
--- a/private/property.te
+++ b/private/property.te
@@ -537,3 +537,7 @@
   -coredomain
   -appdomain
 } sqlite_log_prop:file no_rw_file_perms;
+
+# Only one of system_property_type and vendor_property_type can be assigned.
+# Property types having both attributes won't be accessible from anywhere.
+neverallow domain system_and_vendor_property_type:{file property_service} *;
diff --git a/private/technical_debt.cil b/private/technical_debt.cil
index fdcd0a3..9b3e3c6 100644
--- a/private/technical_debt.cil
+++ b/private/technical_debt.cil
@@ -63,3 +63,9 @@
 ; Unfortunately, we can't currently express this in module policy language:
 ;     typeattribute { appdomain -isolated_app } hal_cas_client;
 (typeattributeset hal_bufferhub_client ((and (appdomain) ((not (isolated_app))))))
+
+; Properties having both system_property_type and vendor_property_type are illegal
+; Unfortunately, we can't currently express this in module policy language:
+;     typeattribute { system_property_type && vendor_property_type } system_and_vendor_property_type;
+(typeattribute system_and_vendor_property_type)
+(typeattributeset system_and_vendor_property_type ((and (system_property_type) (vendor_property_type))))