diff --git a/phpseclib/Math/BigInteger.php b/phpseclib/Math/BigInteger.php
index b8b1b26b..e057f546 100644
--- a/phpseclib/Math/BigInteger.php
+++ b/phpseclib/Math/BigInteger.php
@@ -2751,6 +2751,12 @@ class BigInteger
      */
     function setPrecision($bits)
     {
+        if ($bits < 1) {
+            $this->precision = -1;
+            $this->bitmask = false;
+
+            return;
+        }
         $this->precision = $bits;
         if (MATH_BIGINTEGER_MODE != self::MODE_BCMATH) {
             $this->bitmask = new static(chr((1 << ($bits & 0x7)) - 1) . str_repeat(chr(0xFF), $bits >> 3), 256);
@@ -2762,6 +2768,18 @@ class BigInteger
         $this->value = $temp->value;
     }
 
+    /**
+     * Get Precision
+     *
+     * @return int
+     * @see self::setPrecision()
+     * @access public
+     */
+    function getPrecision()
+    {
+        return $this->precision;
+    }
+
     /**
      * Logical And
      *
diff --git a/tests/Unit/Math/BigInteger/TestCase.php b/tests/Unit/Math/BigInteger/TestCase.php
index c922a775..b13fde5e 100644
--- a/tests/Unit/Math/BigInteger/TestCase.php
+++ b/tests/Unit/Math/BigInteger/TestCase.php
@@ -348,6 +348,17 @@ abstract class Unit_Math_BigInteger_TestCase extends PhpseclibTestCase
         $num = $this->getInstance(50);
         $str = print_r($num, true);
         $this->assertContains('[value] => 0x32', $str);
-        return $str;
+    }
+
+    public function testPrecision()
+    {
+        $a = $this->getInstance(50);
+        $this->assertSame($a->getPrecision(), -1);
+        $b = $a;
+        $c = clone $a;
+        $b->setPrecision(4);
+        $this->assertSame($a->getPrecision(), 4);
+        $this->assertSame($b->getPrecision(), 4);
+        $this->assertSame($c->getPrecision(), -1);
     }
 }