diff --git a/src/main/java/com/zaxxer/hikari/pool/PoolBase.java b/src/main/java/com/zaxxer/hikari/pool/PoolBase.java
index 803f4bbbd..f37af52b0 100644
--- a/src/main/java/com/zaxxer/hikari/pool/PoolBase.java
+++ b/src/main/java/com/zaxxer/hikari/pool/PoolBase.java
@@ -157,6 +157,9 @@ void quietlyCloseConnection(final Connection connection, final String closureRea
    boolean isConnectionDead(final Connection connection)
    {
       try {
+         if (connection.isClosed()) {
+            return true;
+         }
          setNetworkTimeout(connection, validationTimeout);
          try {
             final var validationSeconds = (int) Math.max(1000L, validationTimeout) / 1000;