diff --git a/src/Type/Definition/IntType.php b/src/Type/Definition/IntType.php
index b732792..4473ce5 100644
--- a/src/Type/Definition/IntType.php
+++ b/src/Type/Definition/IntType.php
@@ -74,7 +74,10 @@ values. Int can represent values between -(2^31) and 2^31 - 1. ';
      */
     public function parseValue($value)
     {
-        return (is_int($value) && $value <= self::MAX_INT && $value >= self::MIN_INT) ? $value : null;
+        // Below is a fix against PHP bug where (in some combinations of OSs and versions)
+        // boundary values are treated as "double" vs "integer" and failing is_int() check
+        $isInt = is_int($value) || $value === self::MIN_INT || $value === self::MAX_INT;
+        return $isInt && $value <= self::MAX_INT && $value >= self::MIN_INT ? $value : null;
     }
 
     /**