diff --git a/CHANGELOG.md b/CHANGELOG.md
index acede3f..a34d540 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,8 @@ All notable changes to this project will be documented in this file.
 Updates should follow the [Keep a CHANGELOG](http://keepachangelog.com/) principles.
 
 ## [Unreleased][unreleased]
+### Added
+- Input type validation for InputParam
 
 ## 3.0.0
 
diff --git a/src/Params/GetInputParam.php b/src/Params/GetInputParam.php
index b6b7a9c..750a1c3 100644
--- a/src/Params/GetInputParam.php
+++ b/src/Params/GetInputParam.php
@@ -4,6 +4,8 @@
 
 namespace Tomaj\NetteApi\Params;
 
+use Tomaj\NetteApi\Validation\InputValidator;
+
 class GetInputParam extends InputParam
 {
     protected $type = self::TYPE_GET;
@@ -14,6 +16,8 @@ public function getValue()
             return $_GET[$this->key];
         }
         $value = $this->isMulti() ? filter_input(INPUT_GET, $this->key, FILTER_DEFAULT, FILTER_REQUIRE_ARRAY) : filter_input(INPUT_GET, $this->key);
-        return $value !== null && $value !== false ? $value : $this->default;
+        $value = $value !== null && $value !== false ? $value : $this->default;
+        $inputValidator = new InputValidator();
+        return $inputValidator->transformType($value, $this->valueType);
     }
 }
diff --git a/src/Params/InputParam.php b/src/Params/InputParam.php
index 468520f..02c15b3 100644
--- a/src/Params/InputParam.php
+++ b/src/Params/InputParam.php
@@ -7,21 +7,22 @@
 use Nette\Application\UI\Form;
 use Nette\Forms\Controls\BaseControl;
 use Nette\Utils\Html;
+use Tomaj\NetteApi\Validation\InputValidator;
 use Tomaj\NetteApi\ValidationResult\ValidationResult;
 use Tomaj\NetteApi\ValidationResult\ValidationResultInterface;
 
 abstract class InputParam implements ParamInterface
 {
-    const TYPE_POST      = 'POST';
-    const TYPE_GET       = 'GET';
-    const TYPE_PUT       = 'PUT';
-    const TYPE_FILE      = 'FILE';
-    const TYPE_COOKIE    = 'COOKIE';
-    const TYPE_POST_RAW  = 'POST_RAW';
-    const TYPE_POST_JSON = 'POST_JSON';
+    public const TYPE_POST      = 'POST';
+    public const TYPE_GET       = 'GET';
+    public const TYPE_PUT       = 'PUT';
+    public const TYPE_FILE      = 'FILE';
+    public const TYPE_COOKIE    = 'COOKIE';
+    public const TYPE_POST_RAW  = 'POST_RAW';
+    public const TYPE_POST_JSON = 'POST_JSON';
 
-    const OPTIONAL = false;
-    const REQUIRED = true;
+    public const OPTIONAL = false;
+    public const REQUIRED = true;
 
     /** @var string */
     protected $type;
@@ -47,9 +48,17 @@ abstract class InputParam implements ParamInterface
     /** @var array */
     protected $examples = [];
 
-    public function __construct(string $key)
+    /** @var string|null */
+    protected $valueType;
+
+    /**
+     * InputParam constructor.
+     * @param string|null $valueType
+     */
+    public function __construct(string $key, $valueType = null)
     {
         $this->key = $key;
+        $this->valueType = $valueType;
     }
 
     public function setRequired(): self
@@ -238,6 +247,7 @@ public function validate(): ValidationResultInterface
             }
         }
 
-        return new ValidationResult(ValidationResult::STATUS_OK);
+        $inputValidator = new InputValidator();
+        return $inputValidator->validate($value, $this->valueType);
     }
 }
diff --git a/src/Params/PostInputParam.php b/src/Params/PostInputParam.php
index e30e5fd..0e6a23d 100644
--- a/src/Params/PostInputParam.php
+++ b/src/Params/PostInputParam.php
@@ -4,6 +4,8 @@
 
 namespace Tomaj\NetteApi\Params;
 
+use Tomaj\NetteApi\Validation\InputValidator;
+
 class PostInputParam extends InputParam
 {
     protected $type = self::TYPE_POST;
@@ -14,6 +16,8 @@ public function getValue()
             return $_POST[$this->key];
         }
         $value = $this->isMulti() ? filter_input(INPUT_POST, $this->key, FILTER_DEFAULT, FILTER_REQUIRE_ARRAY) : filter_input(INPUT_POST, $this->key);
-        return $value !== null && $value !== false ? $value : $this->default;
+        $value = $value !== null && $value !== false ? $value : $this->default;
+        $inputValidator = new InputValidator();
+        return $inputValidator->transformType($value, $this->valueType);
     }
 }
diff --git a/src/Validation/InputType.php b/src/Validation/InputType.php
new file mode 100644
index 0000000..08f90d2
--- /dev/null
+++ b/src/Validation/InputType.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace Tomaj\NetteApi\Validation;
+
+class InputType
+{
+    public const BOOLEAN = 'boolean';
+    public const INTEGER = 'integer';
+    public const DOUBLE = 'double';
+    public const FLOAT = 'float';
+    public const STRING = 'string';
+    public const ARRAY = 'array';
+}
diff --git a/src/Validation/InputValidator.php b/src/Validation/InputValidator.php
new file mode 100644
index 0000000..ffd1baf
--- /dev/null
+++ b/src/Validation/InputValidator.php
@@ -0,0 +1,103 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tomaj\NetteApi\Validation;
+
+use Tomaj\NetteApi\ValidationResult\ValidationResult;
+use Tomaj\NetteApi\ValidationResult\ValidationResultInterface;
+
+class InputValidator
+{
+    /**
+     * Summary of validate
+     * @param mixed $value
+     * @param ?string $expectedType
+     */
+    public function validate($value, $expectedType = null): ValidationResultInterface
+    {
+        if ($value === null || $expectedType === null) {
+            return new ValidationResult(ValidationResult::STATUS_OK);
+        }
+
+        switch ($expectedType) {
+            case InputType::BOOLEAN:
+                if (!is_bool($value)) {
+                    return new ValidationResult(ValidationResult::STATUS_ERROR, ['Value ' . $value .  ' has invalid type. Expected boolean.']);
+                }
+                break;
+            case InputType::INTEGER:
+                if (!is_int($value)) {
+                    return new ValidationResult(ValidationResult::STATUS_ERROR, ['Value ' . $value .  ' has invalid type. Expected integer.']);
+                }
+                break;
+            case InputType::DOUBLE:
+                if (!is_float($value) && !is_int($value)) {
+                    return new ValidationResult(ValidationResult::STATUS_ERROR, ['Value ' . $value .  ' has invalid type. Expected double.']);
+                }
+                break;
+            case InputType::FLOAT:
+                if (!is_float($value) && !is_int($value)) {
+                    return new ValidationResult(ValidationResult::STATUS_ERROR, ['Value ' . $value .  ' has invalid type. Expected float.']);
+                }
+                break;
+            case InputType::STRING:
+                if (!is_string($value)) {
+                    return new ValidationResult(ValidationResult::STATUS_ERROR, ['Value ' . $value .  ' has invalid type. Expected string.']);
+                }
+                break;
+            case InputType::ARRAY:
+                if (!is_array($value)) {
+                    return new ValidationResult(ValidationResult::STATUS_ERROR, ['Value ' . $value .  ' has invalid type. Expected array.']);
+                }
+                break;
+            default:
+                return new ValidationResult(ValidationResult::STATUS_ERROR, ['Value ' . $value .  ' has invalid type.']);
+        }
+        return new ValidationResult(ValidationResult::STATUS_OK);
+    }
+
+    /**
+     * Summary of transformType
+     * @param mixed $value
+     * @param ?string $expectedType
+     */
+    public function transformType($value, $expectedType = null)
+    {
+        if ($value === null || $expectedType === null) {
+            return $value;
+        }
+        switch ($expectedType) {
+            case InputType::BOOLEAN:
+                if ($value === '1' || $value === 1 || $value === true || strtolower((string) $value) === 'true') {
+                    return true;
+                } else {
+                    return false;
+                }
+                // no break
+            case InputType::INTEGER:
+                if (is_numeric($value)) {
+                    settype($value, 'integer');
+                }
+                break;
+            case InputType::DOUBLE:
+                if (is_numeric($value)) {
+                    settype($value, 'double');
+                }
+                break;
+            case InputType::FLOAT:
+                if (is_numeric($value)) {
+                    settype($value, 'float');
+                }
+                break;
+            case InputType::STRING:
+                if (is_string($value)) {
+                    settype($value, 'string');
+                }
+                break;
+            default:
+                return $value;
+        }
+        return $value;
+    }
+}