diff --git a/phpseclib/Crypt/RSA.php b/phpseclib/Crypt/RSA.php
index e9cfbfd2..3fe65c47 100644
--- a/phpseclib/Crypt/RSA.php
+++ b/phpseclib/Crypt/RSA.php
@@ -525,13 +525,13 @@ class RSA
         $finalMax = $max;
         extract(self::_generateMinMax($temp));
 
-        $n = self::$one->copy();
+        $n = clone self::$one;
         if (!empty($partial)) {
             extract(unserialize($partial));
         } else {
             $exponents = $coefficients = $primes = array();
             $lcm = array(
-                'top' => self::$one->copy(),
+                'top' => clone self::$one,
                 'bottom' => false
             );
         }
@@ -716,13 +716,13 @@ class RSA
             }
 
             if (is_object($key->modulus)) {
-                $this->modulus = $key->modulus->copy();
+                $this->modulus = clone $key->modulus;
             }
             if (is_object($key->exponent)) {
-                $this->exponent = $key->exponent->copy();
+                $this->exponent = clone $key->exponent;
             }
             if (is_object($key->publicExponent)) {
-                $this->publicExponent = $key->publicExponent->copy();
+                $this->publicExponent = clone $key->publicExponent;
             }
 
             $this->primes = array();
@@ -730,13 +730,13 @@ class RSA
             $this->coefficients = array();
 
             foreach ($this->primes as $prime) {
-                $this->primes[] = $prime->copy();
+                $this->primes[] = clone $prime;
             }
             foreach ($this->exponents as $exponent) {
-                $this->exponents[] = $exponent->copy();
+                $this->exponents[] = clone $exponent;
             }
             foreach ($this->coefficients as $coefficient) {
-                $this->coefficients[] = $coefficient->copy();
+                $this->coefficients[] = clone $coefficient;
             }
 
             return true;
diff --git a/phpseclib/Math/BigInteger.php b/phpseclib/Math/BigInteger.php
index e057f546..5cbb95aa 100644
--- a/phpseclib/Math/BigInteger.php
+++ b/phpseclib/Math/BigInteger.php
@@ -711,28 +711,6 @@ class BigInteger
         return $result;
     }
 
-    /**
-     * Copy an object
-     *
-     * PHP5 passes objects by reference while PHP4 passes by value.  As such, we need a function to guarantee
-     * that all objects are passed by value, when appropriate.  More information can be found here:
-     *
-     * {@link http://php.net/language.oop5.basic#51624}
-     *
-     * @access public
-     * @see self::__clone()
-     * @return \phpseclib\Math\BigInteger
-     */
-    function copy()
-    {
-        $temp = new static();
-        $temp->value = $this->value;
-        $temp->is_negative = $this->is_negative;
-        $temp->precision = $this->precision;
-        $temp->bitmask = $this->bitmask;
-        return $temp;
-    }
-
     /**
      *  __toString() magic method
      *
@@ -747,22 +725,6 @@ class BigInteger
         return $this->toString();
     }
 
-    /**
-     * __clone() magic method
-     *
-     * @access public
-     * @return \phpseclib\Math\BigInteger
-     */
-    function __clone()
-    {
-        $temp = new static();
-        $temp->value = $this->value;
-        $temp->is_negative = $this->is_negative;
-        $temp->precision = $this->precision;
-        $temp->bitmask = $this->bitmask;
-        return $temp;
-    }
-
     /**
      *  __sleep() magic method
      *
@@ -1443,8 +1405,8 @@ class BigInteger
             $zero = new static();
         }
 
-        $x = $this->copy();
-        $y = $y->copy();
+        $x = clone $this;
+        $y = clone $y;
 
         $x_sign = $x->is_negative;
         $y_sign = $y->is_negative;
diff --git a/tests/Unit/Math/BigInteger/TestCase.php b/tests/Unit/Math/BigInteger/TestCase.php
index b13fde5e..b960a338 100644
--- a/tests/Unit/Math/BigInteger/TestCase.php
+++ b/tests/Unit/Math/BigInteger/TestCase.php
@@ -352,13 +352,16 @@ abstract class Unit_Math_BigInteger_TestCase extends PhpseclibTestCase
 
     public function testPrecision()
     {
-        $a = $this->getInstance(50);
+        $a = $this->getInstance(51);
         $this->assertSame($a->getPrecision(), -1);
         $b = $a;
         $c = clone $a;
-        $b->setPrecision(4);
-        $this->assertSame($a->getPrecision(), 4);
-        $this->assertSame($b->getPrecision(), 4);
+        $b->setPrecision(1);
+        $this->assertSame($a->getPrecision(), 1);
+        $this->assertSame("$a", '1');
+        $this->assertSame($b->getPrecision(), 1);
+        $this->assertSame("$b", '1');
         $this->assertSame($c->getPrecision(), -1);
+        $this->assertSame("$c", '51');
     }
 }