diff --git a/src/Assert.php b/src/Assert.php
index d65dd8a9..8e3f83f0 100644
--- a/src/Assert.php
+++ b/src/Assert.php
@@ -701,7 +701,8 @@ public static function false($value, $message = '')
     }
 
     /**
-     * @psalm-assert string $value
+     * @psalm-assert string|object $value note: can be an object implementing __toString
+     * @psalm-assert !empty $value
      *
      * @param mixed  $value
      * @param string $message
@@ -719,7 +720,8 @@ public static function ip($value, $message = '')
     }
 
     /**
-     * @psalm-assert string $value
+     * @psalm-assert string|object $value note: can be an object implementing __toString
+     * @psalm-assert !empty $value
      *
      * @param mixed  $value
      * @param string $message
@@ -737,7 +739,8 @@ public static function ipv4($value, $message = '')
     }
 
     /**
-     * @psalm-assert string $value
+     * @psalm-assert string|object $value note: can be an object implementing __toString
+     * @psalm-assert !empty $value
      *
      * @param mixed  $value
      * @param string $message
@@ -755,7 +758,8 @@ public static function ipv6($value, $message = '')
     }
 
     /**
-     * @psalm-assert string $value
+     * @psalm-assert string|object $value note: can be an object implementing __toString
+     * @psalm-assert !empty $value
      *
      * @param mixed  $value
      * @param string $message
diff --git a/tests/static-analysis/assert-email.php b/tests/static-analysis/assert-email.php
index ed4a297f..dcb12bfc 100644
--- a/tests/static-analysis/assert-email.php
+++ b/tests/static-analysis/assert-email.php
@@ -4,10 +4,14 @@
 
 use Webmozart\Assert\Assert;
 
-/**
- * @psalm-param mixed $value
- */
-function consume($value): string
+function consume(?string $value): string
+{
+    Assert::email($value);
+
+    return $value;
+}
+
+function consumeObject(?object $value): object
 {
     Assert::email($value);
 
diff --git a/tests/static-analysis/assert-ip.php b/tests/static-analysis/assert-ip.php
index d8df3372..534266ef 100644
--- a/tests/static-analysis/assert-ip.php
+++ b/tests/static-analysis/assert-ip.php
@@ -4,12 +4,17 @@
 
 use Webmozart\Assert\Assert;
 
-/**
- * @psalm-param mixed $value
- */
-function consume($value): string
+function consume(?string $value): string
 {
     Assert::ip($value);
 
     return $value;
 }
+
+function consumeObject(?object $value): object
+{
+    Assert::ip($value);
+
+    return $value;
+}
+
diff --git a/tests/static-analysis/assert-ipv4.php b/tests/static-analysis/assert-ipv4.php
index 338f8444..5c3b92dd 100644
--- a/tests/static-analysis/assert-ipv4.php
+++ b/tests/static-analysis/assert-ipv4.php
@@ -4,12 +4,17 @@
 
 use Webmozart\Assert\Assert;
 
-/**
- * @psalm-param mixed $value
- */
-function consume($value): string
+function consume(?string $value): string
 {
     Assert::ipv4($value);
 
     return $value;
 }
+
+function consumeObject(?object $value): object
+{
+    Assert::ipv4($value);
+
+    return $value;
+}
+
diff --git a/tests/static-analysis/assert-ipv6.php b/tests/static-analysis/assert-ipv6.php
index 374c577e..c2b2a6cf 100644
--- a/tests/static-analysis/assert-ipv6.php
+++ b/tests/static-analysis/assert-ipv6.php
@@ -4,12 +4,17 @@
 
 use Webmozart\Assert\Assert;
 
-/**
- * @psalm-param mixed $value
- */
-function consume($value): string
+function consume(?string $value): string
 {
     Assert::ipv6($value);
 
     return $value;
 }
+
+function consumeObject(?object $value): object
+{
+    Assert::ipv6($value);
+
+    return $value;
+}
+