diff --git a/src/Schema/Type/Number.php b/src/Schema/Type/Number.php
index e52c6ab..d909dc1 100644
--- a/src/Schema/Type/Number.php
+++ b/src/Schema/Type/Number.php
@@ -50,7 +50,11 @@ public function validate(mixed $value, callable $fail): void
             }
         }
 
-        if ($this->multipleOf !== null && $value % $this->multipleOf !== 0) {
+        if (
+            $this->multipleOf !== null &&
+            (float) $value !== 0.0 &&
+            $value % $this->multipleOf !== 0
+        ) {
             $fail(sprintf('must be a multiple of %d', $this->multipleOf));
         }
     }
@@ -85,7 +89,7 @@ public function maximum(?float $maximum, bool $exclusive = false): static
 
     public function multipleOf(?float $number): static
     {
-        if ($number <= 0) {
+        if ($number !== null && $number <= 0) {
             throw new InvalidArgumentException('multipleOf must be a positive number');
         }