diff --git a/apps/explorer/config/test.exs b/apps/explorer/config/test.exs
index 1eb16cbe3b..728b931ac9 100644
--- a/apps/explorer/config/test.exs
+++ b/apps/explorer/config/test.exs
@@ -60,7 +60,8 @@ for repo <- [
     ownership_timeout: :timer.minutes(1),
     timeout: :timer.seconds(60),
     queue_target: 1000,
-    log: false
+    log: false,
+    pool_size: 1
 end
 
 config :logger, :explorer,