diff --git a/README.md b/README.md
index 766099c..be445fe 100644
--- a/README.md
+++ b/README.md
@@ -207,9 +207,11 @@ Method                                             | Description
 
 ### Function Assertions
 
-Method                                      | Description
-------------------------------------------- | -----------------------------------------------------------------------------------------------------
-`throws($closure, $class, $message = '')`   | Check that a function throws a certain exception. Subclasses of the exception class will be accepted.
+Method                                    | Description
+------------------------------------------| -----------------------------------------------------------------------------------------------------
+`throws($closure, $class, $message = '')` | Check that a function throws a certain exception. Subclasses of the exception class will be accepted.
+`isStatic($closure, $message = '')`       | Check that a function is static.
+`isNotStatic($closure, $message = '')`    | Check that a function is not static.
 
 ### Collection Assertions
 
diff --git a/src/Assert.php b/src/Assert.php
index f02b8c9..6018317 100644
--- a/src/Assert.php
+++ b/src/Assert.php
@@ -18,6 +18,7 @@
 use DateTime;
 use DateTimeImmutable;
 use Exception;
+use ReflectionFunction;
 use ResourceBundle;
 use SimpleXMLElement;
 use Throwable;
@@ -1940,6 +1941,41 @@ public static function isMap($array, $message = '')
         }
     }
 
+    /**
+     * @param Closure $closure
+     * @param string $message
+     * @return void
+     * @throws InvalidArgumentException
+     */
+    public static function isStatic(Closure $closure, $message = '')
+    {
+        $reflection = new ReflectionFunction($closure);
+
+        if (!$reflection->isStatic()) {
+            static::reportInvalidArgument(
+                $message ?: 'Closure is not static.'
+            );
+        }
+    }
+
+    /**
+     * @param Closure $closure
+     * @param string $message
+     * @return void
+     * @throws InvalidArgumentException
+     */
+    public static function isNotStatic(Closure $closure, $message = '')
+    {
+        Assert::isCallable($closure);
+        $reflection = new ReflectionFunction($closure);
+
+        if ($reflection->isStatic()) {
+            static::reportInvalidArgument(
+                $message ?: 'Closure is not static.'
+            );
+        }
+    }
+
     /**
      * @psalm-pure
      *
diff --git a/src/Mixin.php b/src/Mixin.php
index fad0d47..9f05eda 100644
--- a/src/Mixin.php
+++ b/src/Mixin.php
@@ -5035,6 +5035,106 @@ public static function allNullOrIsMap($array, $message = '')
         }
     }
 
+    /**
+     * @param Closure|null $closure
+     * @param string       $message
+     *
+     * @return void
+     * @return void
+     *
+     * @throws InvalidArgumentException
+     */
+    public static function nullOrIsStatic($closure, $message = '')
+    {
+        null === $closure || static::isStatic($closure, $message);
+    }
+
+    /**
+     * @param iterable<Closure> $closure
+     * @param string            $message
+     *
+     * @return void
+     * @return void
+     *
+     * @throws InvalidArgumentException
+     */
+    public static function allIsStatic($closure, $message = '')
+    {
+        static::isIterable($closure);
+
+        foreach ($closure as $entry) {
+            static::isStatic($entry, $message);
+        }
+    }
+
+    /**
+     * @param iterable<Closure|null> $closure
+     * @param string                 $message
+     *
+     * @return void
+     * @return void
+     *
+     * @throws InvalidArgumentException
+     */
+    public static function allNullOrIsStatic($closure, $message = '')
+    {
+        static::isIterable($closure);
+
+        foreach ($closure as $entry) {
+            null === $entry || static::isStatic($entry, $message);
+        }
+    }
+
+    /**
+     * @param Closure|null $closure
+     * @param string       $message
+     *
+     * @return void
+     * @return void
+     *
+     * @throws InvalidArgumentException
+     */
+    public static function nullOrIsNotStatic($closure, $message = '')
+    {
+        null === $closure || static::isNotStatic($closure, $message);
+    }
+
+    /**
+     * @param iterable<Closure> $closure
+     * @param string            $message
+     *
+     * @return void
+     * @return void
+     *
+     * @throws InvalidArgumentException
+     */
+    public static function allIsNotStatic($closure, $message = '')
+    {
+        static::isIterable($closure);
+
+        foreach ($closure as $entry) {
+            static::isNotStatic($entry, $message);
+        }
+    }
+
+    /**
+     * @param iterable<Closure|null> $closure
+     * @param string                 $message
+     *
+     * @return void
+     * @return void
+     *
+     * @throws InvalidArgumentException
+     */
+    public static function allNullOrIsNotStatic($closure, $message = '')
+    {
+        static::isIterable($closure);
+
+        foreach ($closure as $entry) {
+            null === $entry || static::isNotStatic($entry, $message);
+        }
+    }
+
     /**
      * @psalm-pure
      *
diff --git a/tests/AssertTest.php b/tests/AssertTest.php
index 87a1bb1..903c950 100644
--- a/tests/AssertTest.php
+++ b/tests/AssertTest.php
@@ -548,6 +548,10 @@ public function getTests()
             array('throws', array(function () { trigger_error('test'); }, 'Throwable'), true, false, 70000),
             array('throws', array(function () { trigger_error('test'); }, 'Unthrowable'), false, false, 70000),
             array('throws', array(function () { throw new Error(); }, 'Throwable'), true, true, 70000),
+            array('isStatic', array(static function () {}), true),
+            array('isStatic', array(function () {}), false),
+            array('isNotStatic', array(static function () {}), false),
+            array('isNotStatic', array(function () {}), true),
             array('ip', array('192.168.0.1'), true),
             array('ip', array(new ToStringClass('192.168.0.1')), true),
             array('ip', array('255.255.255.255'), true),
diff --git a/tests/static-analysis/assert-isStatic.php b/tests/static-analysis/assert-isStatic.php
new file mode 100644
index 0000000..2de93a5
--- /dev/null
+++ b/tests/static-analysis/assert-isStatic.php
@@ -0,0 +1,20 @@
+<?php
+
+namespace Webmozart\Assert\Tests\StaticAnalysis;
+
+use Closure;
+use Webmozart\Assert\Assert;
+
+function isStatic(Closure $closure): Closure
+{
+    Assert::isStatic($closure);
+
+    return $closure;
+}
+
+function isNotStatic(Closure $closure): Closure
+{
+    Assert::isNotStatic($closure);
+
+    return $closure;
+}