diff --git a/src/Symfony/Component/Form/Extension/Validator/ValidatorTypeGuesser.php b/src/Symfony/Component/Form/Extension/Validator/ValidatorTypeGuesser.php
index 63d06dca7185..52d25893b936 100644
--- a/src/Symfony/Component/Form/Extension/Validator/ValidatorTypeGuesser.php
+++ b/src/Symfony/Component/Form/Extension/Validator/ValidatorTypeGuesser.php
@@ -220,6 +220,10 @@ public function guessPatternForConstraint(Constraint $constraint)
         switch (get_class($constraint)) {
             case 'Symfony\Component\Validator\Constraints\Length':
                 if (is_numeric($constraint->min)) {
+                    if (is_numeric($constraint->max)) {
+                        return new ValueGuess(sprintf('.{%s,%s}', (string) $constraint->min, (string) $constraint->max), Guess::LOW_CONFIDENCE);
+                    }
+
                     return new ValueGuess(sprintf('.{%s,}', (string) $constraint->min), Guess::LOW_CONFIDENCE);
                 }
                 break;
@@ -234,6 +238,10 @@ public function guessPatternForConstraint(Constraint $constraint)
 
             case 'Symfony\Component\Validator\Constraints\Range':
                 if (is_numeric($constraint->min)) {
+                    if (is_numeric($constraint->max)) {
+                        return new ValueGuess(sprintf('.{%s,%s}', strlen((string) $constraint->min), strlen((string) $constraint->max)), Guess::LOW_CONFIDENCE);
+                    }
+
                     return new ValueGuess(sprintf('.{%s,}', strlen((string) $constraint->min)), Guess::LOW_CONFIDENCE);
                 }
                 break;