diff --git a/phpseclib/Math/BigInteger.php b/phpseclib/Math/BigInteger.php
index 4b116ec7..ed28c78c 100644
--- a/phpseclib/Math/BigInteger.php
+++ b/phpseclib/Math/BigInteger.php
@@ -445,6 +445,9 @@ class BigInteger
                 // (?<=^|-)0*: find any 0's that are preceded by the start of the string or by a - (ie. octals)
                 // [^-0-9].*: find any non-numeric characters and then any characters that follow that
                 $x = preg_replace('#(?<!^)(?:-).*|(?<=^|-)0*|[^-0-9].*#', '', $x);
+                if (!strlen($x)) {
+                    $x = '0';
+                }
 
                 switch (MATH_BIGINTEGER_MODE) {
                     case self::MODE_GMP:
diff --git a/tests/Unit/Math/BigInteger/TestCase.php b/tests/Unit/Math/BigInteger/TestCase.php
index c9d9d6bb..0b9ef016 100644
--- a/tests/Unit/Math/BigInteger/TestCase.php
+++ b/tests/Unit/Math/BigInteger/TestCase.php
@@ -403,4 +403,10 @@ abstract class Unit_Math_BigInteger_TestCase extends PhpseclibTestCase
         $temp = $this->getInstance(48);
         $this->assertSame($temp->toHex(true), '30');
     }
+
+    public function testZeroBase10()
+    {
+        $temp = $this->getInstance('00');
+        $this->assertSame($temp->toString(), '0');
+    }
 }