diff --git a/lib/PgSqlExecutor.php b/lib/PgSqlExecutor.php
index 70c7d29..6a5e191 100644
--- a/lib/PgSqlExecutor.php
+++ b/lib/PgSqlExecutor.php
@@ -205,7 +205,7 @@ class PgSqlExecutor implements Executor {
      */
     public function execute(string $sql, ...$params): Promise {
         return call(function () use ($sql, $params) {
-            return $this->createResult(yield from $this->send("pg_send_query_params", $sql, $params));
+            return $this->createResult(yield from $this->send("pg_send_query_params", sha1($sql), $params));
         });
     }
 
@@ -214,7 +214,7 @@ class PgSqlExecutor implements Executor {
      */
     public function prepare(string $sql): Promise {
         return call(function () use ($sql) {
-            yield from $this->send("pg_send_prepare", $sql, $sql);
+            yield from $this->send("pg_send_prepare", sha1($sql), $sql);
             return new PgSqlStatement($sql, $this->executeCallback);
         });
     }
diff --git a/lib/PgSqlStatement.php b/lib/PgSqlStatement.php
index bd32d11..93687ab 100644
--- a/lib/PgSqlStatement.php
+++ b/lib/PgSqlStatement.php
@@ -35,6 +35,6 @@ class PgSqlStatement implements Statement {
      * @throws \Amp\Postgres\FailureException If executing the statement fails.
      */
     public function execute(...$params): Promise {
-        return ($this->execute)($this->sql, $params);
+        return ($this->execute)(sha1($this->sql), $params);
     }
 }
diff --git a/lib/PqExecutor.php b/lib/PqExecutor.php
index c5d5190..28193c3 100644
--- a/lib/PqExecutor.php
+++ b/lib/PqExecutor.php
@@ -215,14 +215,14 @@ class PqExecutor implements Executor {
      * {@inheritdoc}
      */
     public function execute(string $sql, ...$params): Promise {
-        return new Coroutine($this->send([$this->handle, "execParamsAsync"], $sql, $params));
+        return new Coroutine($this->send([$this->handle, "execParamsAsync"], sha1($sql), $params));
     }
 
     /**
      * {@inheritdoc}
      */
     public function prepare(string $sql): Promise {
-        return new Coroutine($this->send([$this->handle, "prepareAsync"], $sql, $sql));
+        return new Coroutine($this->send([$this->handle, "prepareAsync"], sha1($sql), $sql));
     }
 
     /**