diff --git a/src/Type/Types/ShapedArrayType.php b/src/Type/Types/ShapedArrayType.php
index 476f657f..435c08a6 100644
--- a/src/Type/Types/ShapedArrayType.php
+++ b/src/Type/Types/ShapedArrayType.php
@@ -9,7 +9,10 @@
 use CuyZ\Valinor\Type\TraversableType;
 use CuyZ\Valinor\Type\Type;
 
+use function array_diff;
 use function array_key_exists;
+use function array_keys;
+use function count;
 use function implode;
 use function in_array;
 use function is_array;
@@ -45,9 +48,11 @@ public function accepts($value): bool
             return false;
         }
 
+        $keys = [];
+
         foreach ($this->elements as $shape) {
             $type = $shape->type();
-            $key = $shape->key()->value();
+            $keys[] = $key = $shape->key()->value();
             $valueExists = array_key_exists($key, $value);
 
             if (! $valueExists && ! $shape->isOptional()) {
@@ -59,7 +64,9 @@ public function accepts($value): bool
             }
         }
 
-        return true;
+        $excess = array_diff(array_keys($value), $keys);
+
+        return count($excess) === 0;
     }
 
     public function matches(Type $other): bool
diff --git a/tests/Integration/Mapping/Type/ShapedArrayValuesMappingTest.php b/tests/Integration/Mapping/Type/ShapedArrayValuesMappingTest.php
index a155c090..e5e3e8bf 100644
--- a/tests/Integration/Mapping/Type/ShapedArrayValuesMappingTest.php
+++ b/tests/Integration/Mapping/Type/ShapedArrayValuesMappingTest.php
@@ -15,6 +15,10 @@ final class ShapedArrayValuesMappingTest extends IntegrationTest
     public function test_values_are_mapped_properly(): void
     {
         $source = [
+            'basicShapedArrayWithExcessiveKey' => [
+                'foo' => 'foo',
+                'bar' => 42,
+            ],
             'basicShapedArrayWithStringKeys' => [
                 'foo' => 'fiz',
                 'bar' => 42,
@@ -47,6 +51,7 @@ public function test_values_are_mapped_properly(): void
                 $this->mappingFail($error);
             }
 
+            self::assertSame(['foo' => 'foo'], $result->basicShapedArrayWithExcessiveKey);
             self::assertSame($source['basicShapedArrayWithStringKeys'], $result->basicShapedArrayWithStringKeys);
             self::assertSame($source['basicShapedArrayWithIntegerKeys'], $result->basicShapedArrayWithIntegerKeys);
             self::assertInstanceOf(SimpleObject::class, $result->shapedArrayWithObject['foo']);
@@ -79,6 +84,9 @@ public function test_value_that_cannot_be_casted_throws_exception(): void
 
 class ShapedArrayValues
 {
+    /** @var array{foo: string} */
+    public array $basicShapedArrayWithExcessiveKey;
+
     /** @var array{foo: string, bar: int} */
     public array $basicShapedArrayWithStringKeys;
 
@@ -106,6 +114,7 @@ class ShapedArrayValues
 class ShapedArrayValuesWithConstructor extends ShapedArrayValues
 {
     /**
+     * @param array{foo: string} $basicShapedArrayWithExcessiveKey
      * @param array{foo: string, bar: int} $basicShapedArrayWithStringKeys
      * @param array{0: string, 1: float} $basicShapedArrayWithIntegerKeys
      * @param array{foo: SimpleObject} $shapedArrayWithObject
@@ -117,6 +126,7 @@ class ShapedArrayValuesWithConstructor extends ShapedArrayValues
      * @param array{0: int, float, optionalString?: string, mandatoryString: string} $advancedShapedArray
      */
     public function __construct(
+        array $basicShapedArrayWithExcessiveKey,
         array $basicShapedArrayWithStringKeys,
         array $basicShapedArrayWithIntegerKeys,
         array $shapedArrayWithObject,
@@ -124,6 +134,7 @@ public function __construct(
         array $shapedArrayOnSeveralLines,
         array $advancedShapedArray
     ) {
+        $this->basicShapedArrayWithExcessiveKey = $basicShapedArrayWithExcessiveKey;
         $this->basicShapedArrayWithStringKeys = $basicShapedArrayWithStringKeys;
         $this->basicShapedArrayWithIntegerKeys = $basicShapedArrayWithIntegerKeys;
         $this->shapedArrayWithObject = $shapedArrayWithObject;
diff --git a/tests/Unit/Type/Types/ShapedArrayTypeTest.php b/tests/Unit/Type/Types/ShapedArrayTypeTest.php
index 89487776..2d4c7e22 100644
--- a/tests/Unit/Type/Types/ShapedArrayTypeTest.php
+++ b/tests/Unit/Type/Types/ShapedArrayTypeTest.php
@@ -69,6 +69,7 @@ public function test_accepts_correct_values(): void
 
     public function test_does_not_accept_incorrect_values(): void
     {
+        self::assertFalse($this->type->accepts(['foo' => 42]));
         self::assertFalse($this->type->accepts(['foo' => new stdClass()]));
         self::assertFalse($this->type->accepts(['bar' => 'foo']));
 
@@ -80,6 +81,11 @@ public function test_does_not_accept_incorrect_values(): void
         self::assertFalse($this->type->accepts(new stdClass()));
     }
 
+    public function test_does_not_accept_array_with_excessive_keys(): void
+    {
+        self::assertFalse($this->type->accepts(['foo' => 'foo', 'fiz' => 42]));
+    }
+
     public function test_matches_valid_array_shaped_type(): void
     {
         $otherA = new ShapedArrayType(