diff --git a/generator/mql-specifications b/generator/mql-specifications
index e15b26d69..d23e9a860 160000
--- a/generator/mql-specifications
+++ b/generator/mql-specifications
@@ -1 +1 @@
-Subproject commit e15b26d690ddf44c7c8e352485ab6100a1d4af74
+Subproject commit d23e9a8603cb29c5ea90f571bdabcde1d834de4c
diff --git a/src/Builder/Expression/FactoryTrait.php b/src/Builder/Expression/FactoryTrait.php
index bdc0350e6..22956a9fe 100644
--- a/src/Builder/Expression/FactoryTrait.php
+++ b/src/Builder/Expression/FactoryTrait.php
@@ -1670,13 +1670,13 @@ public static function replaceAll(
      * New in MongoDB 4.4
      *
      * @see https://www.mongodb.com/docs/manual/reference/operator/aggregation/replaceOne/
-     * @param ResolvesToNull|ResolvesToString|null|string $input The string on which you wish to apply the find. Can be any valid expression that resolves to a string or a null. If input refers to a field that is missing, $replaceAll returns null.
-     * @param ResolvesToNull|ResolvesToString|null|string $find The string to search for within the given input. Can be any valid expression that resolves to a string or a null. If find refers to a field that is missing, $replaceAll returns null.
-     * @param ResolvesToNull|ResolvesToString|null|string $replacement The string to use to replace all matched instances of find in input. Can be any valid expression that resolves to a string or a null.
+     * @param ResolvesToNull|ResolvesToString|null|string $input The string on which you wish to apply the find. Can be any valid expression that resolves to a string or a null. If input refers to a field that is missing, $replaceOne returns null.
+     * @param Regex|ResolvesToNull|ResolvesToRegex|ResolvesToString|null|string $find The string or regex to search for within the given input. Can be any valid expression that resolves to a string, a regex, or a null. If find refers to a field that is missing, $replaceOne returns null.
+     * @param ResolvesToNull|ResolvesToString|null|string $replacement The string to use to replace the first matched instance of find in input. Can be any valid expression that resolves to a string or a null.
      */
     public static function replaceOne(
         ResolvesToNull|ResolvesToString|null|string $input,
-        ResolvesToNull|ResolvesToString|null|string $find,
+        Regex|ResolvesToNull|ResolvesToRegex|ResolvesToString|null|string $find,
         ResolvesToNull|ResolvesToString|null|string $replacement,
     ): ReplaceOneOperator {
         return new ReplaceOneOperator($input, $find, $replacement);
diff --git a/src/Builder/Expression/ReplaceOneOperator.php b/src/Builder/Expression/ReplaceOneOperator.php
index a66d30ff5..da11ce4ee 100644
--- a/src/Builder/Expression/ReplaceOneOperator.php
+++ b/src/Builder/Expression/ReplaceOneOperator.php
@@ -8,6 +8,7 @@
 
 namespace MongoDB\Builder\Expression;
 
+use MongoDB\BSON\Regex;
 use MongoDB\Builder\Type\Encode;
 use MongoDB\Builder\Type\OperatorInterface;
 
@@ -25,23 +26,23 @@ final class ReplaceOneOperator implements ResolvesToString, OperatorInterface
     public const NAME = '$replaceOne';
     public const PROPERTIES = ['input' => 'input', 'find' => 'find', 'replacement' => 'replacement'];
 
-    /** @var ResolvesToNull|ResolvesToString|null|string $input The string on which you wish to apply the find. Can be any valid expression that resolves to a string or a null. If input refers to a field that is missing, $replaceAll returns null. */
+    /** @var ResolvesToNull|ResolvesToString|null|string $input The string on which you wish to apply the find. Can be any valid expression that resolves to a string or a null. If input refers to a field that is missing, $replaceOne returns null. */
     public readonly ResolvesToNull|ResolvesToString|null|string $input;
 
-    /** @var ResolvesToNull|ResolvesToString|null|string $find The string to search for within the given input. Can be any valid expression that resolves to a string or a null. If find refers to a field that is missing, $replaceAll returns null. */
-    public readonly ResolvesToNull|ResolvesToString|null|string $find;
+    /** @var Regex|ResolvesToNull|ResolvesToRegex|ResolvesToString|null|string $find The string or regex to search for within the given input. Can be any valid expression that resolves to a string, a regex, or a null. If find refers to a field that is missing, $replaceOne returns null. */
+    public readonly Regex|ResolvesToNull|ResolvesToRegex|ResolvesToString|null|string $find;
 
-    /** @var ResolvesToNull|ResolvesToString|null|string $replacement The string to use to replace all matched instances of find in input. Can be any valid expression that resolves to a string or a null. */
+    /** @var ResolvesToNull|ResolvesToString|null|string $replacement The string to use to replace the first matched instance of find in input. Can be any valid expression that resolves to a string or a null. */
     public readonly ResolvesToNull|ResolvesToString|null|string $replacement;
 
     /**
-     * @param ResolvesToNull|ResolvesToString|null|string $input The string on which you wish to apply the find. Can be any valid expression that resolves to a string or a null. If input refers to a field that is missing, $replaceAll returns null.
-     * @param ResolvesToNull|ResolvesToString|null|string $find The string to search for within the given input. Can be any valid expression that resolves to a string or a null. If find refers to a field that is missing, $replaceAll returns null.
-     * @param ResolvesToNull|ResolvesToString|null|string $replacement The string to use to replace all matched instances of find in input. Can be any valid expression that resolves to a string or a null.
+     * @param ResolvesToNull|ResolvesToString|null|string $input The string on which you wish to apply the find. Can be any valid expression that resolves to a string or a null. If input refers to a field that is missing, $replaceOne returns null.
+     * @param Regex|ResolvesToNull|ResolvesToRegex|ResolvesToString|null|string $find The string or regex to search for within the given input. Can be any valid expression that resolves to a string, a regex, or a null. If find refers to a field that is missing, $replaceOne returns null.
+     * @param ResolvesToNull|ResolvesToString|null|string $replacement The string to use to replace the first matched instance of find in input. Can be any valid expression that resolves to a string or a null.
      */
     public function __construct(
         ResolvesToNull|ResolvesToString|null|string $input,
-        ResolvesToNull|ResolvesToString|null|string $find,
+        Regex|ResolvesToNull|ResolvesToRegex|ResolvesToString|null|string $find,
         ResolvesToNull|ResolvesToString|null|string $replacement,
     ) {
         $this->input = $input;
diff --git a/tests/Builder/Expression/Pipelines.php b/tests/Builder/Expression/Pipelines.php
index 862087926..e37008cda 100644
--- a/tests/Builder/Expression/Pipelines.php
+++ b/tests/Builder/Expression/Pipelines.php
@@ -4520,6 +4520,32 @@ enum Pipelines: string
     ]
     JSON;
 
+    /**
+     * Replace Using Regex
+     *
+     * @see https://www.mongodb.com/docs/manual/reference/operator/aggregation/replaceOne/#replace-using-regex
+     */
+    case ReplaceOneReplaceUsingRegex = <<<'JSON'
+    [
+        {
+            "$project": {
+                "item": {
+                    "$replaceOne": {
+                        "input": "$item",
+                        "find": {
+                            "$regularExpression": {
+                                "pattern": "\\bblue paint\\b",
+                                "options": ""
+                            }
+                        },
+                        "replacement": "red paint"
+                    }
+                }
+            }
+        }
+    ]
+    JSON;
+
     /**
      * Example
      *
diff --git a/tests/Builder/Expression/ReplaceOneOperatorTest.php b/tests/Builder/Expression/ReplaceOneOperatorTest.php
index 90bf8082b..4f8a69b3e 100644
--- a/tests/Builder/Expression/ReplaceOneOperatorTest.php
+++ b/tests/Builder/Expression/ReplaceOneOperatorTest.php
@@ -4,6 +4,7 @@
 
 namespace MongoDB\Tests\Builder\Expression;
 
+use MongoDB\BSON\Regex;
 use MongoDB\Builder\Expression;
 use MongoDB\Builder\Pipeline;
 use MongoDB\Builder\Stage;
@@ -28,4 +29,19 @@ public function testExample(): void
 
         $this->assertSamePipeline(Pipelines::ReplaceOneExample, $pipeline);
     }
+
+    public function testReplaceUsingRegex(): void
+    {
+        $pipeline = new Pipeline(
+            Stage::project(
+                item: Expression::replaceOne(
+                    input: Expression::stringFieldPath('item'),
+                    find: new Regex('\bblue paint\b'),
+                    replacement: 'red paint',
+                ),
+            ),
+        );
+
+        $this->assertSamePipeline(Pipelines::ReplaceOneReplaceUsingRegex, $pipeline);
+    }
 }