diff --git a/spa/include/spa/pod/filter.h b/spa/include/spa/pod/filter.h
index d6e1fc5d1..05df98340 100644
--- a/spa/include/spa/pod/filter.h
+++ b/spa/include/spa/pod/filter.h
@@ -301,6 +301,8 @@ static inline int spa_pod_filter_part(struct spa_pod_builder *b,
 					p2 = spa_pod_object_find_prop(of, p2, p1->key);
 					if (p2 != NULL)
 						res = spa_pod_filter_prop(b, p1, p2);
+					else if ((p1->flags & SPA_POD_PROP_FLAG_MANDATORY) != 0)
+						res = -EINVAL;
 					else
 						spa_pod_builder_raw_padded(b, p1, SPA_POD_PROP_SIZE(p1));
 					if (res < 0)
@@ -312,7 +314,10 @@ static inline int spa_pod_filter_part(struct spa_pod_builder *b,
 						p1 = spa_pod_object_find_prop(op, p1, p2->key);
 						if (p1 != NULL)
 							continue;
-
+						if ((p2->flags & SPA_POD_PROP_FLAG_MANDATORY) != 0)
+							res = -EINVAL;
+						if (res < 0)
+							break;
 						spa_pod_builder_raw_padded(b, p2, SPA_POD_PROP_SIZE(p2));
 					}
 				}