diff --git a/src/test/subscription/t/008_diff_schema.pl b/src/test/subscription/t/008_diff_schema.pl
index 4f0851718ca6ebb0fb039c7ca1b92176b84ad065..3854934f79d23eb1659c9c5fb051bec900542c31 100644
--- a/src/test/subscription/t/008_diff_schema.pl
+++ b/src/test/subscription/t/008_diff_schema.pl
@@ -105,6 +105,9 @@ $node_subscriber->safe_psql('postgres',
 $node_subscriber->safe_psql('postgres',
 	"ALTER SUBSCRIPTION tap_sub REFRESH PUBLICATION");
 
+$node_subscriber->poll_query_until('postgres', $synced_query)
+  or die "Timed out while waiting for subscriber to synchronize data";
+
 # Add replica identity column.  (The serial is not necessary, but it's
 # a convenient way to get a default on the new column so that rows
 # from the publisher that don't have the column yet can be inserted.)