diff --git a/config/initializers/fill_shards.rb b/config/initializers/fill_shards.rb
index cad662e12f3b2fe36eec1dbd23c250c4f7514c03..40a9a2719535e934b0c1d92740f1310023c0bcb9 100644
--- a/config/initializers/fill_shards.rb
+++ b/config/initializers/fill_shards.rb
@@ -1,5 +1,8 @@
 # The `table_exists?` check is needed because during our migration rollback testing,
 # `Shard.connected?` could be cached and return true even though the table doesn't exist
-if Shard.connected? && Shard.table_exists? && !Gitlab::Database.read_only?
-  Shard.populate!
-end
+return unless Shard.connected?
+return unless Shard.table_exists?
+return unless Shard.connection.index_exists?(:shards, :name, unique: true)
+return if Gitlab::Database.read_only?
+
+Shard.populate!