diff --git a/src/PgSqlHandle.php b/src/PgSqlHandle.php
index 96b16d5..a596f37 100644
--- a/src/PgSqlHandle.php
+++ b/src/PgSqlHandle.php
@@ -366,7 +366,7 @@ final class PgSqlHandle implements Handle
 
         $modifiedSql = Internal\parseNamedParams($sql, $names);
 
-        $name = Handle::STATEMENT_NAME_PREFIX . \sha1($modifiedSql);
+        $name = Handle::STATEMENT_NAME_PREFIX . \sha1($sql);
 
         if (isset($this->statements[$name])) {
             $storage = $this->statements[$name];
diff --git a/src/Pool.php b/src/Pool.php
index bf901af..e05ff66 100644
--- a/src/Pool.php
+++ b/src/Pool.php
@@ -54,9 +54,7 @@ final class Pool extends ConnectionPool implements Link
         $this->statements = $statements = new class($maxConnections) extends LRUCache implements \IteratorAggregate {
             public function getIterator(): \Iterator
             {
-                foreach ($this->data as $key => $data) {
-                    yield $key => $data;
-                }
+                yield from $this->data;
             }
         };
 
@@ -147,8 +145,10 @@ final class Pool extends ConnectionPool implements Link
         }
 
         return call(function () use ($sql) {
-            if ($this->statements->containsKey($sql)) {
-                $statement = $this->statements->get($sql);
+            $name = Handle::STATEMENT_NAME_PREFIX . \sha1($sql);
+
+            if ($this->statements->containsKey($name)) {
+                $statement = $this->statements->get($name);
 
                 if ($statement instanceof Promise) {
                     $statement = yield $statement; // Wait for prior request to resolve.
@@ -162,17 +162,17 @@ final class Pool extends ConnectionPool implements Link
             }
 
             $promise = parent::prepare($sql);
-            $this->statements->put($sql, $promise); // Insert promise into queue so subsequent requests get promise.
+            $this->statements->put($name, $promise); // Insert promise into queue so subsequent requests get promise.
 
             try {
                 $statement = yield $promise;
                 \assert($statement instanceof StatementPool);
             } catch (\Throwable $exception) {
-                $this->statements->remove($sql);
+                $this->statements->remove($name);
                 throw $exception;
             }
 
-            $this->statements->put($sql, $statement); // Replace promise in queue with statement object.
+            $this->statements->put($name, $statement); // Replace promise in queue with statement object.
 
             return $statement;
         });
diff --git a/src/PqHandle.php b/src/PqHandle.php
index 64f8e92..e9fce5c 100644
--- a/src/PqHandle.php
+++ b/src/PqHandle.php
@@ -387,7 +387,7 @@ final class PqHandle implements Handle
 
         $modifiedSql = Internal\parseNamedParams($sql, $names);
 
-        $name = Handle::STATEMENT_NAME_PREFIX . \sha1($modifiedSql);
+        $name = Handle::STATEMENT_NAME_PREFIX . \sha1($sql);
 
         if (isset($this->statements[$name])) {
             $storage = $this->statements[$name];
diff --git a/test/AbstractLinkTest.php b/test/AbstractLinkTest.php
index e83dc02..63b0687 100644
--- a/test/AbstractLinkTest.php
+++ b/test/AbstractLinkTest.php
@@ -346,6 +346,24 @@ abstract class AbstractLinkTest extends TestCase
         });
     }
 
+    public function testPrepareSimilarQueryReturnsDifferentStatements()
+    {
+        Loop::run(function () {
+            /** @var Statement $statement1 */
+            $statement1 = $this->connection->prepare("SELECT * FROM test WHERE domain=\$1");
+
+            /** @var Statement $statement2 */
+            $statement2 = $this->connection->prepare("SELECT * FROM test WHERE domain=:domain");
+
+            list($statement1, $statement2) = yield [$statement1, $statement2];
+
+            $this->assertInstanceOf(Statement::class, $statement1);
+            $this->assertInstanceOf(Statement::class, $statement2);
+
+            $this->assertNotSame($statement1, $statement2);
+        });
+    }
+
     public function testPrepareThenExecuteWithUnconsumedTupleResult()
     {
         Loop::run(function () {