diff --git a/src/BigDecimal.php b/src/BigDecimal.php
index 8efe1c0..ef93b2b 100644
--- a/src/BigDecimal.php
+++ b/src/BigDecimal.php
@@ -211,15 +211,15 @@ public function multipliedBy($that)
      * Returns the result of the division of this number by the given one, at the given scale.
      *
      * @param BigNumber|number|string $that         The divisor.
-     * @param int                     $scale        The desired scale.
+     * @param int|null                $scale        The desired scale, or null to use the scale of this number.
      * @param int                     $roundingMode An optional rounding mode.
      *
      * @return BigDecimal
      *
-     * @throws \InvalidArgumentException If the rounding mode is invalid.
+     * @throws \InvalidArgumentException If the scale or rounding mode is invalid.
      * @throws ArithmeticException       If the number is invalid, is zero, or rounding was necessary.
      */
-    public function dividedBy($that, $scale, $roundingMode = RoundingMode::UNNECESSARY)
+    public function dividedBy($that, $scale = null, $roundingMode = RoundingMode::UNNECESSARY)
     {
         $that = BigDecimal::of($that);
 
diff --git a/tests/BigDecimalTest.php b/tests/BigDecimalTest.php
index 19cb72b..1c751f6 100644
--- a/tests/BigDecimalTest.php
+++ b/tests/BigDecimalTest.php
@@ -578,12 +578,12 @@ public function providerMultipliedBy()
     /**
      * @dataProvider providerDividedBy
      *
-     * @param string $a             The base number.
-     * @param string $b             The number to multiply.
-     * @param int    $scale         The desired scale of the result.
-     * @param int    $roundingMode  The rounding mode.
-     * @param string $unscaledValue The expected unscaled value of the result.
-     * @param int    $expectedScale The expected scale of the result.
+     * @param string   $a             The base number.
+     * @param string   $b             The number to divide.
+     * @param int|null $scale         The desired scale of the result.
+     * @param int      $roundingMode  The rounding mode.
+     * @param string   $unscaledValue The expected unscaled value of the result.
+     * @param int      $expectedScale The expected scale of the result.
      */
     public function testDividedBy($a, $b, $scale, $roundingMode, $unscaledValue, $expectedScale)
     {
@@ -606,6 +606,7 @@ public function providerDividedBy()
             ['-32479478384783947298.3343898', '1', 7, RoundingMode::UNNECESSARY, '-324794783847839472983343898', 7],
 
             ['1.5', '2', 2, RoundingMode::UNNECESSARY, '75', 2],
+            ['1.5', '3', null, RoundingMode::UNNECESSARY, '5', 1],
             ['0.123456789', '0.00244140625', 10, RoundingMode::UNNECESSARY, '505679007744', 10],
             ['1.234', '123.456', 50, RoundingMode::DOWN, '999546397096941420425090720580611715914981855883', 50],
             ['1', '3', 10, RoundingMode::UP, '3333333334', 10],