diff --git a/lib/BigInteger.php b/lib/BigInteger.php
index 2ac6dad..3c710df 100644
--- a/lib/BigInteger.php
+++ b/lib/BigInteger.php
@@ -625,6 +625,20 @@ public function equals($x) {
     public function sign() {
         return $this->value[0] === "-" ? -1 : ($this->value === "0" ? 0 : 1);
     }
+
+    public function shiftLeft($n) {
+        return $this->mul((new static(2))->pow($n));
+    }
+
+    public function shiftRight($n) {
+        $newInt = $this->div((new static(2))->pow($n));
+
+        if ($newInt->add($n)->cmp(0) < 0) {
+            return $newInt->sub(1);
+        }
+
+        return $newInt;
+    }
 }
 
 }
diff --git a/test/test.php b/test/test.php
index 2fc71bf..4fbe543 100644
--- a/test/test.php
+++ b/test/test.php
@@ -74,6 +74,8 @@ function testOp() {
     testB((new BigInteger(20))->binaryAnd(18), "16", "binaryAnd");
     testB((new BigInteger(20))->binaryOr(18), "22", "binaryOr");
     testB((new BigInteger(20))->binaryXor(18), "6", "binaryXor");
+    testB((new BigInteger(3))->shiftLeft(4), "48", "shiftLeft");
+    testB((new BigInteger(3))->shiftRight(4), "0", "shiftRight");
     testB((new BigInteger(20))->setbit(3), "28", "setbit");
     test((new BigInteger(20))->testbit(4), true, "testbit true");
     test((new BigInteger(20))->testbit(3), false, "testbit false");