diff --git a/overlay/inventory/os.cf b/overlay/inventory/os.cf
index 4185d5b..a6928db 100644
--- a/overlay/inventory/os.cf
+++ b/overlay/inventory/os.cf
@@ -130,14 +130,19 @@ amzn_2::
      string => "Amazon 2",
      meta => { "inventory", "attribute_name=OS" };
 
-@endif
 any::
-  "description" string => "$(sys.os_release[PRETTY_NAME])",
-                    if => isvariable("sys.os_release[PRETTY_NAME]"),
-                meta => { "inventory", "attribute_name=OS", "derived-from=sys.os_release" };
+  "description"
+    string => "$(sys.os_release[PRETTY_NAME])",
+    if => and(
+      strcmp("$(sys.os_name_human)", "Unknown"),
+      isvariable("sys.os_release[PRETTY_NAME]")
+    ),
+    meta => { "inventory", "attribute_name=OS", "derived-from=sys.os_release" };
+
 darwin::
   "product_name" string => execresult("/usr/bin/sw_vers --productName", useshell);
   "product_version" string => execresult("/usr/bin/sw_vers --productVersion", useshell);
   "description" string => "$(product_name) $(product_version)",
     meta => { "inventory", "attribute_name=OS", "derived-from=sw_vers command" };
+@endif
 }