diff --git a/src/conn/pool/mod.rs b/src/conn/pool/mod.rs
index 34303845..16888050 100644
--- a/src/conn/pool/mod.rs
+++ b/src/conn/pool/mod.rs
@@ -285,6 +285,11 @@ impl Pool {
 impl Drop for Conn {
     fn drop(&mut self) {
         if std::thread::panicking() {
+            // Try to decrease the number of existing connections.
+            if let Some(pool) = self.inner.pool.take() {
+                pool.cancel_connection();
+            }
+
             return;
         }