diff --git a/src/Psl/Type/Internal/LiteralScalarType.php b/src/Psl/Type/Internal/LiteralScalarType.php
index d90a3448..6f64c66f 100644
--- a/src/Psl/Type/Internal/LiteralScalarType.php
+++ b/src/Psl/Type/Internal/LiteralScalarType.php
@@ -41,14 +41,16 @@ public function matches(mixed $value): bool
      */
     public function coerce(mixed $value): string|int|float|bool
     {
-        if ($value === $this->value) {
+        $expectedScalarValue = $this->value;
+        if ($value === $expectedScalarValue) {
             /** @var T $value */
             return $value;
         }
 
-        if (Type\string()->matches($this->value)) {
-            $coerced_value = Type\string()->coerce($value);
-            if ($this->value === $coerced_value) {
+        $stringType = Type\string();
+        if ($stringType->matches($this->value)) {
+            $coerced_value = $stringType->coerce($value);
+            if ($expectedScalarValue === $coerced_value) {
                 /** @var T $coerced_value */
                 return $coerced_value;
             }
@@ -56,9 +58,10 @@ public function coerce(mixed $value): string|int|float|bool
             throw CoercionException::withValue($value, $this->toString());
         }
 
-        if (Type\int()->matches($this->value)) {
-            $coerced_value = Type\int()->coerce($value);
-            if ($this->value === $coerced_value) {
+        $intType = Type\int();
+        if ($intType->matches($this->value)) {
+            $coerced_value = $intType->coerce($value);
+            if ($expectedScalarValue === $coerced_value) {
                 /** @var T $coerced_value */
                 return $coerced_value;
             }
@@ -66,9 +69,10 @@ public function coerce(mixed $value): string|int|float|bool
             throw CoercionException::withValue($value, $this->toString());
         }
 
-        if (Type\float()->matches($this->value)) {
-            $coerced_value = Type\float()->coerce($value);
-            if ($this->value === $coerced_value) {
+        $floatType = Type\float();
+        if ($floatType->matches($this->value)) {
+            $coerced_value = $floatType->coerce($value);
+            if ($expectedScalarValue === $coerced_value) {
                 /** @var T $coerced_value */
                 return $coerced_value;
             }
@@ -77,7 +81,7 @@ public function coerce(mixed $value): string|int|float|bool
         }
 
         /** @var bool $literal_value */
-        $literal_value = $this->value;
+        $literal_value = $expectedScalarValue;
         $coerced_value = Type\bool()->coerce($value);
         if ($literal_value === $coerced_value) {
             /** @var T $coerced_value */
diff --git a/src/Psl/Type/array_key.php b/src/Psl/Type/array_key.php
index f2e32948..b11a3013 100644
--- a/src/Psl/Type/array_key.php
+++ b/src/Psl/Type/array_key.php
@@ -9,5 +9,8 @@
  */
 function array_key(): TypeInterface
 {
-    return new Internal\ArrayKeyType();
+    /** @var Internal\ArrayKeyType $instance */
+    static $instance = new Internal\ArrayKeyType();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/bool.php b/src/Psl/Type/bool.php
index 1051d588..7e9266df 100644
--- a/src/Psl/Type/bool.php
+++ b/src/Psl/Type/bool.php
@@ -9,5 +9,8 @@
  */
 function bool(): TypeInterface
 {
-    return new Internal\BoolType();
+    /** @var Internal\BoolType $instance */
+    static $instance = new Internal\BoolType();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/f32.php b/src/Psl/Type/f32.php
index 93a0890e..3965b958 100644
--- a/src/Psl/Type/f32.php
+++ b/src/Psl/Type/f32.php
@@ -11,5 +11,8 @@
  */
 function f32(): TypeInterface
 {
-    return new Internal\F32Type();
+    /** @var Internal\F32Type $instance */
+    static $instance = new Internal\F32Type();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/f64.php b/src/Psl/Type/f64.php
index fcbe021d..86e5cd38 100644
--- a/src/Psl/Type/f64.php
+++ b/src/Psl/Type/f64.php
@@ -11,5 +11,8 @@
  */
 function f64(): TypeInterface
 {
-    return new Internal\F64Type();
+    /** @var Internal\F64Type $instance */
+    static $instance = new Internal\F64Type();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/float.php b/src/Psl/Type/float.php
index 275e7139..05500938 100644
--- a/src/Psl/Type/float.php
+++ b/src/Psl/Type/float.php
@@ -9,5 +9,8 @@
  */
 function float(): TypeInterface
 {
-    return new Internal\FloatType();
+    /** @var Internal\FloatType $instance */
+    static $instance = new Internal\FloatType();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/i16.php b/src/Psl/Type/i16.php
index 6a879e02..f6c4a490 100644
--- a/src/Psl/Type/i16.php
+++ b/src/Psl/Type/i16.php
@@ -11,5 +11,8 @@
  */
 function i16(): TypeInterface
 {
-    return new Internal\I16Type();
+    /** @var Internal\I16Type $instance */
+    static $instance = new Internal\I16Type();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/i32.php b/src/Psl/Type/i32.php
index bb8d050e..5c47897d 100644
--- a/src/Psl/Type/i32.php
+++ b/src/Psl/Type/i32.php
@@ -11,5 +11,8 @@
  */
 function i32(): TypeInterface
 {
-    return new Internal\I32Type();
+    /** @var Internal\I32Type $instance */
+    static $instance = new Internal\I32Type();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/i64.php b/src/Psl/Type/i64.php
index aff40727..26982eb1 100644
--- a/src/Psl/Type/i64.php
+++ b/src/Psl/Type/i64.php
@@ -11,5 +11,8 @@
  */
 function i64(): TypeInterface
 {
-    return new Internal\I64Type();
+    /** @var Internal\I64Type $instance */
+    static $instance = new Internal\I64Type();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/i8.php b/src/Psl/Type/i8.php
index 1603e580..1b35e0f6 100644
--- a/src/Psl/Type/i8.php
+++ b/src/Psl/Type/i8.php
@@ -11,5 +11,8 @@
  */
 function i8(): TypeInterface
 {
-    return new Internal\I8Type();
+    /** @var Internal\I8Type $instance */
+    static $instance = new Internal\I8Type();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/int.php b/src/Psl/Type/int.php
index cfe9e03c..949a03d3 100644
--- a/src/Psl/Type/int.php
+++ b/src/Psl/Type/int.php
@@ -9,5 +9,8 @@
  */
 function int(): TypeInterface
 {
-    return new Internal\IntType();
+    /** @var Internal\IntType $instance */
+    static $instance = new Internal\IntType();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/mixed.php b/src/Psl/Type/mixed.php
index c7ce83c5..3d966c44 100644
--- a/src/Psl/Type/mixed.php
+++ b/src/Psl/Type/mixed.php
@@ -9,5 +9,8 @@
  */
 function mixed(): TypeInterface
 {
-    return new Internal\MixedType();
+    /** @var Internal\MixedType $instance */
+    static $instance = new Internal\MixedType();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/non_empty_string.php b/src/Psl/Type/non_empty_string.php
index 18f97233..5864ac25 100644
--- a/src/Psl/Type/non_empty_string.php
+++ b/src/Psl/Type/non_empty_string.php
@@ -9,5 +9,8 @@
  */
 function non_empty_string(): TypeInterface
 {
-    return new Internal\NonEmptyStringType();
+    /** @var Internal\NonEmptyStringType $instance */
+    static $instance = new Internal\NonEmptyStringType();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/nonnull.php b/src/Psl/Type/nonnull.php
index 8f2c5d62..f79ec2d5 100644
--- a/src/Psl/Type/nonnull.php
+++ b/src/Psl/Type/nonnull.php
@@ -11,5 +11,8 @@
  */
 function nonnull(): TypeInterface
 {
-    return new Internal\NonNullType();
+    /** @var Internal\NonNullType $instance */
+    static $instance = new Internal\NonNullType();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/null.php b/src/Psl/Type/null.php
index 9376bc5d..d64d63fc 100644
--- a/src/Psl/Type/null.php
+++ b/src/Psl/Type/null.php
@@ -9,5 +9,8 @@
  */
 function null(): TypeInterface
 {
-    return new Internal\NullType();
+    /** @var Internal\NullType $instance */
+    static $instance = new Internal\NullType();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/num.php b/src/Psl/Type/num.php
index 9fd101a9..d9118b2c 100644
--- a/src/Psl/Type/num.php
+++ b/src/Psl/Type/num.php
@@ -9,5 +9,8 @@
  */
 function num(): TypeInterface
 {
-    return new Internal\NumType();
+    /** @var Internal\NumType $instance */
+    static $instance = new Internal\NumType();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/numeric_string.php b/src/Psl/Type/numeric_string.php
index 85c26746..e02c3d2f 100644
--- a/src/Psl/Type/numeric_string.php
+++ b/src/Psl/Type/numeric_string.php
@@ -9,5 +9,8 @@
  */
 function numeric_string(): TypeInterface
 {
-    return new Internal\NumericStringType();
+    /** @var Internal\NumericStringType $instance */
+    static $instance = new Internal\NumericStringType();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/object.php b/src/Psl/Type/object.php
index 1f12ae65..5ede48f4 100644
--- a/src/Psl/Type/object.php
+++ b/src/Psl/Type/object.php
@@ -9,5 +9,8 @@
  */
 function object(): TypeInterface
 {
-    return new Internal\ObjectType();
+    /** @var Internal\ObjectType $instance */
+    static $instance = new Internal\ObjectType();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/positive_int.php b/src/Psl/Type/positive_int.php
index 93275697..d92473b8 100644
--- a/src/Psl/Type/positive_int.php
+++ b/src/Psl/Type/positive_int.php
@@ -11,5 +11,8 @@
  */
 function positive_int(): TypeInterface
 {
-    return new Internal\PositiveIntType();
+    /** @var Internal\PositiveIntType $instance */
+    static $instance = new Internal\PositiveIntType();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/scalar.php b/src/Psl/Type/scalar.php
index 2990f484..3b4d2e42 100644
--- a/src/Psl/Type/scalar.php
+++ b/src/Psl/Type/scalar.php
@@ -9,5 +9,8 @@
  */
 function scalar(): TypeInterface
 {
-    return new Internal\ScalarType();
+    /** @var Internal\ScalarType $instance */
+    static $instance = new Internal\ScalarType();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/string.php b/src/Psl/Type/string.php
index 617c54b9..5071debb 100644
--- a/src/Psl/Type/string.php
+++ b/src/Psl/Type/string.php
@@ -9,5 +9,8 @@
  */
 function string(): TypeInterface
 {
-    return new Internal\StringType();
+    /** @var Internal\StringType $instance */
+    static $instance = new Internal\StringType();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/u16.php b/src/Psl/Type/u16.php
index 350a3d6b..53afa82c 100644
--- a/src/Psl/Type/u16.php
+++ b/src/Psl/Type/u16.php
@@ -11,5 +11,8 @@
  */
 function u16(): TypeInterface
 {
-    return new Internal\U16Type();
+    /** @var Internal\U16Type $instance */
+    static $instance = new Internal\U16Type();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/u32.php b/src/Psl/Type/u32.php
index e524ad2e..a3b9e1dc 100644
--- a/src/Psl/Type/u32.php
+++ b/src/Psl/Type/u32.php
@@ -11,5 +11,8 @@
  */
 function u32(): TypeInterface
 {
-    return new Internal\U32Type();
+    /** @var Internal\U32Type $instance */
+    static $instance = new Internal\U32Type();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/u8.php b/src/Psl/Type/u8.php
index 02f5a517..f1eee385 100644
--- a/src/Psl/Type/u8.php
+++ b/src/Psl/Type/u8.php
@@ -11,5 +11,8 @@
  */
 function u8(): TypeInterface
 {
-    return new Internal\U8Type();
+    /** @var Internal\U8Type $instance */
+    static $instance = new Internal\U8Type();
+
+    return $instance;
 }
diff --git a/src/Psl/Type/uint.php b/src/Psl/Type/uint.php
index c9899e3e..70838a64 100644
--- a/src/Psl/Type/uint.php
+++ b/src/Psl/Type/uint.php
@@ -11,5 +11,8 @@
  */
 function uint(): TypeInterface
 {
-    return new Internal\UIntType();
+    /** @var Internal\UIntType $instance */
+    static $instance = new Internal\UIntType();
+
+    return $instance;
 }
diff --git a/tests/benchmark/Type/ShapeTypeBench.php b/tests/benchmark/Type/ShapeTypeBench.php
index e7fb3846..88fd79ca 100644
--- a/tests/benchmark/Type/ShapeTypeBench.php
+++ b/tests/benchmark/Type/ShapeTypeBench.php
@@ -98,6 +98,58 @@ public function provideHappyPathCoercion(): array
                     'war' => null,
                 ]),
             ],
+            'real-life-type-usage' => [
+                'type' => Type\shape([
+                    'name' => Type\string(),
+                    'articles' => Type\vec(Type\shape([
+                        'title' => Type\string(),
+                        'content' => Type\string(),
+                        'likes' => Type\int(),
+                        'comments' => Type\optional(Type\vec(Type\shape([
+                            'user' => Type\string(),
+                            'comment' => Type\string()
+                        ]))),
+                    ])),
+                    'dictionary' => Type\dict(Type\string(), Type\vec(Type\shape([
+                        'title' => Type\string(),
+                        'content' => Type\string(),
+                    ]))),
+                    'pagination' => Type\optional(Type\shape([
+                        'currentPage' => Type\uint(),
+                        'totalPages' => Type\uint(),
+                        'perPage' => Type\uint(),
+                        'totalRows' => Type\uint(),
+                    ]))
+                ]),
+                'value' => [
+                    'name' => 'ok',
+                    'articles' => [
+                        [
+                            'title' => 'ok',
+                            'content' => 'ok',
+                            'likes' => 1,
+                            'comments' => [
+                                [
+                                    'user' => 'ok',
+                                    'comment' => 'ok'
+                                ],
+                                [
+                                    'user' => 'ok',
+                                    'comment' => 'ok',
+                                ]
+                            ]
+                        ]
+                    ],
+                    'dictionary' => [
+                        'key' => [
+                            [
+                                'title' => 'ok',
+                                'content' => 'ok',
+                            ]
+                        ]
+                    ]
+                ]
+            ]
         ];
     }
 
@@ -146,6 +198,58 @@ public function provideHappyPathAssertion(): array
                     'war' => null,
                 ],
             ],
+            'real-life-type-usage' => [
+                'type' => Type\shape([
+                    'name' => Type\string(),
+                    'articles' => Type\vec(Type\shape([
+                        'title' => Type\string(),
+                        'content' => Type\string(),
+                        'likes' => Type\int(),
+                        'comments' => Type\optional(Type\vec(Type\shape([
+                            'user' => Type\string(),
+                            'comment' => Type\string()
+                        ]))),
+                    ])),
+                    'dictionary' => Type\dict(Type\string(), Type\vec(Type\shape([
+                        'title' => Type\string(),
+                        'content' => Type\string(),
+                    ]))),
+                    'pagination' => Type\optional(Type\shape([
+                        'currentPage' => Type\uint(),
+                        'totalPages' => Type\uint(),
+                        'perPage' => Type\uint(),
+                        'totalRows' => Type\uint(),
+                    ]))
+                ]),
+                'value' => [
+                    'name' => 'ok',
+                    'articles' => [
+                        [
+                            'title' => 'ok',
+                            'content' => 'ok',
+                            'likes' => 1,
+                            'comments' => [
+                                [
+                                    'user' => 'ok',
+                                    'comment' => 'ok'
+                                ],
+                                [
+                                    'user' => 'ok',
+                                    'comment' => 'ok',
+                                ]
+                            ]
+                        ]
+                    ],
+                    'dictionary' => [
+                        'key' => [
+                            [
+                                'title' => 'ok',
+                                'content' => 'ok',
+                            ]
+                        ]
+                    ]
+                ]
+            ]
         ];
     }
 
diff --git a/tests/unit/Type/ArrayKeyTypeTest.php b/tests/unit/Type/ArrayKeyTypeTest.php
index 76baf4c4..9b5d60c8 100644
--- a/tests/unit/Type/ArrayKeyTypeTest.php
+++ b/tests/unit/Type/ArrayKeyTypeTest.php
@@ -40,4 +40,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'array-key'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\array_key(), Type\array_key());
+    }
 }
diff --git a/tests/unit/Type/BoolTypeTest.php b/tests/unit/Type/BoolTypeTest.php
index 4bbddc0a..5ccdebb0 100644
--- a/tests/unit/Type/BoolTypeTest.php
+++ b/tests/unit/Type/BoolTypeTest.php
@@ -36,4 +36,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'bool'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\bool(), Type\bool());
+    }
 }
diff --git a/tests/unit/Type/F32TypeTest.php b/tests/unit/Type/F32TypeTest.php
index 2b554e6b..2c2399a6 100644
--- a/tests/unit/Type/F32TypeTest.php
+++ b/tests/unit/Type/F32TypeTest.php
@@ -67,4 +67,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'f32'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\f32(), Type\f32());
+    }
 }
diff --git a/tests/unit/Type/F64TypeTest.php b/tests/unit/Type/F64TypeTest.php
index b8a6890c..206cc898 100644
--- a/tests/unit/Type/F64TypeTest.php
+++ b/tests/unit/Type/F64TypeTest.php
@@ -73,4 +73,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'f64'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\f64(), Type\f64());
+    }
 }
diff --git a/tests/unit/Type/FloatTypeTest.php b/tests/unit/Type/FloatTypeTest.php
index 620fa7cc..3df2d5f3 100644
--- a/tests/unit/Type/FloatTypeTest.php
+++ b/tests/unit/Type/FloatTypeTest.php
@@ -69,4 +69,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'float'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\float(), Type\float());
+    }
 }
diff --git a/tests/unit/Type/I16TypeTest.php b/tests/unit/Type/I16TypeTest.php
index 11f9b4b9..ece9188a 100644
--- a/tests/unit/Type/I16TypeTest.php
+++ b/tests/unit/Type/I16TypeTest.php
@@ -64,4 +64,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'i16'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\i16(), Type\i16());
+    }
 }
diff --git a/tests/unit/Type/I32TypeTest.php b/tests/unit/Type/I32TypeTest.php
index 09769225..f5536c8c 100644
--- a/tests/unit/Type/I32TypeTest.php
+++ b/tests/unit/Type/I32TypeTest.php
@@ -64,4 +64,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'i32'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\i32(), Type\i32());
+    }
 }
diff --git a/tests/unit/Type/I64TypeTest.php b/tests/unit/Type/I64TypeTest.php
index 88a5b1d8..17934899 100644
--- a/tests/unit/Type/I64TypeTest.php
+++ b/tests/unit/Type/I64TypeTest.php
@@ -64,4 +64,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'i64'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\i64(), Type\i64());
+    }
 }
diff --git a/tests/unit/Type/I8TypeTest.php b/tests/unit/Type/I8TypeTest.php
index 36a43acc..33d2e5d0 100644
--- a/tests/unit/Type/I8TypeTest.php
+++ b/tests/unit/Type/I8TypeTest.php
@@ -61,4 +61,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'i8'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\i8(), Type\i8());
+    }
 }
diff --git a/tests/unit/Type/IntTypeTest.php b/tests/unit/Type/IntTypeTest.php
index faee65b1..7e5d70d2 100644
--- a/tests/unit/Type/IntTypeTest.php
+++ b/tests/unit/Type/IntTypeTest.php
@@ -60,4 +60,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'int'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\int(), Type\int());
+    }
 }
diff --git a/tests/unit/Type/MixedTypeTest.php b/tests/unit/Type/MixedTypeTest.php
index 5f156e7e..95cb3ca8 100644
--- a/tests/unit/Type/MixedTypeTest.php
+++ b/tests/unit/Type/MixedTypeTest.php
@@ -88,4 +88,9 @@ public function testInvalidMatches($value): void
     {
         $this->addToAssertionCount(1);
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\mixed(), Type\mixed());
+    }
 }
diff --git a/tests/unit/Type/NonEmptyStringTypeTest.php b/tests/unit/Type/NonEmptyStringTypeTest.php
index 9b5188c2..1fe75297 100644
--- a/tests/unit/Type/NonEmptyStringTypeTest.php
+++ b/tests/unit/Type/NonEmptyStringTypeTest.php
@@ -49,4 +49,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'non-empty-string'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\non_empty_string(), Type\non_empty_string());
+    }
 }
diff --git a/tests/unit/Type/NonNullTypeTest.php b/tests/unit/Type/NonNullTypeTest.php
index d47c5dd7..7f846513 100644
--- a/tests/unit/Type/NonNullTypeTest.php
+++ b/tests/unit/Type/NonNullTypeTest.php
@@ -38,4 +38,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'nonnull'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\nonnull(), Type\nonnull());
+    }
 }
diff --git a/tests/unit/Type/NullTypeTest.php b/tests/unit/Type/NullTypeTest.php
index d1a15b2b..d4c14c60 100644
--- a/tests/unit/Type/NullTypeTest.php
+++ b/tests/unit/Type/NullTypeTest.php
@@ -38,4 +38,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'null'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\null(), Type\null());
+    }
 }
diff --git a/tests/unit/Type/NumTypeTest.php b/tests/unit/Type/NumTypeTest.php
index 47b06165..92c6bf32 100644
--- a/tests/unit/Type/NumTypeTest.php
+++ b/tests/unit/Type/NumTypeTest.php
@@ -80,4 +80,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'num'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\num(), Type\num());
+    }
 }
diff --git a/tests/unit/Type/NumericStringTypeTest.php b/tests/unit/Type/NumericStringTypeTest.php
index 4aec73b5..f486c7be 100644
--- a/tests/unit/Type/NumericStringTypeTest.php
+++ b/tests/unit/Type/NumericStringTypeTest.php
@@ -49,4 +49,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'numeric-string'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\numeric_string(), Type\numeric_string());
+    }
 }
diff --git a/tests/unit/Type/ObjectTypeTest.php b/tests/unit/Type/ObjectTypeTest.php
index 46b3056a..b92fc84f 100644
--- a/tests/unit/Type/ObjectTypeTest.php
+++ b/tests/unit/Type/ObjectTypeTest.php
@@ -37,4 +37,9 @@ public function getToStringExamples(): iterable
     {
         yield [Type\object(), 'object'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\object(), Type\object());
+    }
 }
diff --git a/tests/unit/Type/PositiveIntTypeTest.php b/tests/unit/Type/PositiveIntTypeTest.php
index 6fc300e7..e7e1b427 100644
--- a/tests/unit/Type/PositiveIntTypeTest.php
+++ b/tests/unit/Type/PositiveIntTypeTest.php
@@ -67,4 +67,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'positive-int'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\positive_int(), Type\positive_int());
+    }
 }
diff --git a/tests/unit/Type/StringTypeTest.php b/tests/unit/Type/StringTypeTest.php
index 23629324..e32ad28a 100644
--- a/tests/unit/Type/StringTypeTest.php
+++ b/tests/unit/Type/StringTypeTest.php
@@ -42,4 +42,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'string'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\string(), Type\string());
+    }
 }
diff --git a/tests/unit/Type/U16TypeTest.php b/tests/unit/Type/U16TypeTest.php
index 7eef10d5..835906f4 100644
--- a/tests/unit/Type/U16TypeTest.php
+++ b/tests/unit/Type/U16TypeTest.php
@@ -64,4 +64,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'u16'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\u16(), Type\u16());
+    }
 }
diff --git a/tests/unit/Type/U32TypeTest.php b/tests/unit/Type/U32TypeTest.php
index 1af02abe..17224892 100644
--- a/tests/unit/Type/U32TypeTest.php
+++ b/tests/unit/Type/U32TypeTest.php
@@ -64,4 +64,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'u32'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\u32(), Type\u32());
+    }
 }
diff --git a/tests/unit/Type/U8TypeTest.php b/tests/unit/Type/U8TypeTest.php
index f8182013..4395d25a 100644
--- a/tests/unit/Type/U8TypeTest.php
+++ b/tests/unit/Type/U8TypeTest.php
@@ -66,4 +66,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'u8'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\u8(), Type\u8());
+    }
 }
diff --git a/tests/unit/Type/UIntTypeTest.php b/tests/unit/Type/UIntTypeTest.php
index 9b65df5d..cd764690 100644
--- a/tests/unit/Type/UIntTypeTest.php
+++ b/tests/unit/Type/UIntTypeTest.php
@@ -60,4 +60,9 @@ public function getToStringExamples(): iterable
     {
         yield [$this->getType(), 'uint'];
     }
+
+    public function testItIsAMemoizedType(): void
+    {
+        static::assertSame(Type\uint(), Type\uint());
+    }
 }