diff --git a/src/Param/ParamValueConverterRegistry.php b/src/Param/ParamValueConverterRegistry.php
index 0358c2d2..dd28e991 100644
--- a/src/Param/ParamValueConverterRegistry.php
+++ b/src/Param/ParamValueConverterRegistry.php
@@ -87,8 +87,16 @@ public function __construct(array $registry = [])
 
             'UUID' => self::stringConverter(),
 
-            'Nullable' => fn (mixed $v, Type $type) => $this->get($type->params)($v, null, false),
-            'LowCardinality' => fn (mixed $v, Type $type) => $this->get($type->params)($v, null, false),
+            'Nullable' => fn (
+                mixed $v,
+                Type $type,
+                bool $nested = false,
+            ) => $this->convertWrappedValue($v, $type, $nested),
+            'LowCardinality' => fn (
+                mixed $v,
+                Type $type,
+                bool $nested = false,
+            ) => $this->convertWrappedValue($v, $type, $nested),
 
             'decimal' => self::decimalConverter(),
             'decimal32' => self::decimalConverter(),
@@ -102,13 +110,17 @@ public function __construct(array $registry = [])
             'date32' => self::dateConverter(),
             'datetime' => self::dateTimeConverter(),
             'datetime32' => self::dateTimeConverter(),
-            'datetime64' => static function (mixed $value) {
+            'datetime64' => static function (mixed $value, Type|string|null $type = null, bool $nested = false) {
                 if ($value instanceof DateTimeInterface) {
-                    return $value->format('U.u');
+                    $value = $nested
+                        ? $value->format('Y-m-d H:i:s.u')
+                        : $value->format('U.u');
                 }
 
                 if (is_string($value) || is_float($value) || is_int($value)) {
-                    return $value;
+                    return $nested
+                        ? "'" . Escaper::escape((string) $value) . "'"
+                        : $value;
                 }
 
                 throw UnsupportedParamValue::type($value);
@@ -236,7 +248,7 @@ public function __construct(array $registry = [])
                 return '(' . $innerExpression . ')';
             },
         ];
-        $this->registry  = array_merge($defaultRegistry, $registry);
+        $this->registry = array_merge($defaultRegistry, $registry);
     }
 
     /**
@@ -359,4 +371,12 @@ private function splitTypes(string $types): array
 
         return $result;
     }
+
+    /** @throws UnsupportedParamType */
+    private function convertWrappedValue(mixed $value, Type $type, bool $nested): mixed
+    {
+        $innerType = Type::fromString($type->params);
+
+        return $this->get($innerType)($value, $innerType, $nested);
+    }
 }
diff --git a/tests/Client/Http/RequestFactoryTest.php b/tests/Client/Http/RequestFactoryTest.php
index 35be86ee..37746830 100644
--- a/tests/Client/Http/RequestFactoryTest.php
+++ b/tests/Client/Http/RequestFactoryTest.php
@@ -129,4 +129,92 @@ public function testMultipleNestedParamsParsed(): void
         self::assertStringContainsString('param_serverIds', $body);
         self::assertStringContainsString('param_sensorIds', $body);
     }
+
+    public function testNestedDateTime64ParamIsQuoted(): void
+    {
+        $requestFactory = new RequestFactory(
+            new ParamValueConverterRegistry(),
+            new Psr17Factory(),
+            new Psr17Factory(),
+        );
+
+        $request = $requestFactory->prepareSqlRequest(
+            'SELECT {inputs:Array(Tuple(DateTime64(6), UUID))}',
+            new RequestSettings(
+                new EmptySettingsProvider(),
+                new EmptySettingsProvider(),
+            ),
+            new RequestOptions(
+                [
+                    'inputs' => [
+                        [
+                            new DateTimeImmutable('2026-07-30 12:00:00.123456'),
+                            'c8965e35-e785-4b05-a675-000000000000',
+                        ],
+                    ],
+                ],
+            ),
+        );
+
+        self::assertStringContainsString(
+            "('2026-07-30 12:00:00.123456','c8965e35-e785-4b05-a675-000000000000')",
+            $request->getBody()->__toString(),
+        );
+    }
+
+    public function testTopLevelDateTime64ParamRemainsNumeric(): void
+    {
+        $requestFactory = new RequestFactory(
+            new ParamValueConverterRegistry(),
+            new Psr17Factory(),
+            new Psr17Factory(),
+        );
+
+        $request = $requestFactory->prepareSqlRequest(
+            'SELECT {value:DateTime64(6)}',
+            new RequestSettings(
+                new EmptySettingsProvider(),
+                new EmptySettingsProvider(),
+            ),
+            new RequestOptions(
+                [
+                    'value' => new DateTimeImmutable('2026-07-30 12:00:00.123456'),
+                ],
+            ),
+        );
+
+        self::assertStringContainsString('1785412800.123456', $request->getBody()->__toString());
+    }
+
+    public function testWrappedNestedDateTime64ParamIsQuoted(): void
+    {
+        $requestFactory = new RequestFactory(
+            new ParamValueConverterRegistry(),
+            new Psr17Factory(),
+            new Psr17Factory(),
+        );
+
+        $request = $requestFactory->prepareSqlRequest(
+            'SELECT {inputs:Array(Tuple(Nullable(DateTime64(6)), LowCardinality(DateTime64(6))))}',
+            new RequestSettings(
+                new EmptySettingsProvider(),
+                new EmptySettingsProvider(),
+            ),
+            new RequestOptions(
+                [
+                    'inputs' => [
+                        [
+                            new DateTimeImmutable('2026-07-30 12:00:00.123456'),
+                            new DateTimeImmutable('2026-07-30 12:01:00.123456'),
+                        ],
+                    ],
+                ],
+            ),
+        );
+
+        self::assertStringContainsString(
+            "('2026-07-30 12:00:00.123456','2026-07-30 12:01:00.123456')",
+            $request->getBody()->__toString(),
+        );
+    }
 }