diff --git a/decimal.js b/decimal.js
index d69768e..b0697fb 100644
--- a/decimal.js
+++ b/decimal.js
@@ -2150,7 +2150,11 @@
       rm = Ctor.rounding;
     } else {
       y = new Ctor(y);
-      if (rm !== void 0) checkInt32(rm, 0, 8);
+      if (rm === void 0) {
+        rm = Ctor.rounding;
+      } else {
+        checkInt32(rm, 0, 8);
+      }
 
       // If x is not finite, return x if y is not NaN, else NaN.
       if (!x.d) return y.s ? x : y;
@@ -2165,7 +2169,6 @@
     // If y is not zero, calculate the nearest multiple of y to x.
     if (y.d[0]) {
       external = false;
-      if (rm < 4) rm = [4, 5, 7, 8][rm];
       x = divide(x, y, 0, rm, 1).times(y);
       external = true;
       finalise(x);
diff --git a/test/modules/toNearest.js b/test/modules/toNearest.js
index b0a7252..e3ac89f 100644
--- a/test/modules/toNearest.js
+++ b/test/modules/toNearest.js
@@ -27,8 +27,7 @@ T('toNearest', function () {
   t(!isMinusZero(new Decimal(1).toNearest(-3)));
   t( isMinusZero(new Decimal(-1).toNearest(-3)));
 
-  t = function (expected, n, v, sd, rm) {
-    if (sd) Decimal.precision = sd;
+  t = function (expected, n, v, rm) {
     T.assertEqual(expected, new Decimal(n).toNearest(v, rm).valueOf());
   }
 
@@ -67,9 +66,9 @@ T('toNearest', function () {
 
   t('0', 1, -3);
   t('-0', -1, -3);
-  t('3', 1.5, -3, 20, 0);
-  t('-0', -1.5, -3, 20, 1);
-  t('-3', -1.5, -3, 20, 2);
+  t('3', 1.5, -3, 0);
+  t('-0', -1.5, -3, 1);
+  t('-3', -1.5, -3, 2);
 
   t('123', 123.456);
   t('123', 123.456, 1);
@@ -87,68 +86,145 @@ T('toNearest', function () {
   t('123.46', 123.456, '-0.02');
   t('123.456', 123.456, '-0.002');
 
-  t('83105511540', '83105511539.5', 1, 11, 4);
-  t('83105511539', '83105511539.499999999999999999999999999999', 1, 11, 4);
-  t('83105511539', '83105511539.5', '1', 11, 5);
-  t('83105511540', '83105511539.5000000000000000000001', 1, 11, 5);
-
-  t('83105511540', '83105511539.5', new Decimal(1), 3, 4);
-  t('83105511539', '83105511539.499999999999999999999999999999', 1, 3, 4);
-  t('83105511539', '83105511539.5', new Decimal('1'), 3, 5);
-  t('83105511540', '83105511539.5000000000000000000001', 1, 3, 5);
-
-  t('83105511540', '83105511539.5', Decimal.ONE, 30, 4);
-  t('83105511539', '83105511539.499999999999999999999999999999', 1, 30, 4);
-  t('83105511539', '83105511539.5', 1, 30, 5);
-  t('83105511540', '83105511539.5000000000000000000001', 1, 30, 5);
-
-  t('83105511540', '83105511539.5', -1, 11, 4);
-  t('83105511539', '83105511539.499999999999999999999999999999', -1, 11, 4);
-  t('83105511539', '83105511539.5', '-1', 11, 5);
-  t('83105511540', '83105511539.5000000000000000000001', -1, 11, 5);
-
-  t('83105511540', '83105511539.5', new Decimal(-1), 3, 4);
-  t('83105511539', '83105511539.499999999999999999999999999999', 1, 3, 4);
-  t('83105511539', '83105511539.5', new Decimal('-1'), 3, 5);
-  t('83105511540', '83105511539.5000000000000000000001', -1, 3, 5);
-
-  t('83105511540', '83105511539.5', 1, 30, 0);
-  t('83105511539', '83105511539.5', 1, 30, 1);
-  t('83105511540', '83105511539.5', 1, 30, 2);
-  t('83105511539', '83105511539.5', 1, 30, 3);
-  t('83105511540', '83105511539.5', 1, 30, 4);
-  t('83105511539', '83105511539.5', 1, 30, 5);
-  t('83105511540', '83105511539.5', 1, 30, 6);
-  t('83105511540', '83105511539.5', 1, 30, 7);
-  t('83105511539', '83105511539.5', 1, 30, 8);
-  t('83105511539', '83105511539.499999999999999999999999999999', void 0, 30, 0);
-  t('83105511539', '83105511539.499999999999999999999999999999', 1, 30, 1);
-  t('83105511539', '83105511539.499999999999999999999999999999', void 0, 30, 2);
-  t('83105511539', '83105511539.499999999999999999999999999999', 1, 30, 3);
-  t('83105511539', '83105511539.499999999999999999999999999999', void 0, 30, 4);
-  t('83105511539', '83105511539.499999999999999999999999999999', 1, 30, 5);
-  t('83105511539', '83105511539.499999999999999999999999999999', void 0, 30, 6);
-  t('83105511539', '83105511539.499999999999999999999999999999', 1, 30, 7);
-  t('83105511539', '83105511539.499999999999999999999999999999', void 0, 30, 8);
-  t('83105511540', '83105511539.5000000000000000000001', void 0, 30, 0);
-  t('83105511540', '83105511539.5000000000000000000001', 1, 30, 1);
-  t('83105511540', '83105511539.5000000000000000000001', void 0, 30, 2);
-  t('83105511540', '83105511539.5000000000000000000001', 1, 30, 3);
-  t('83105511540', '83105511539.5000000000000000000001', void 0, 30, 4);
-  t('83105511540', '83105511539.5000000000000000000001', 1, 30, 5);
-  t('83105511540', '83105511539.5000000000000000000001', void 0, 30, 6);
-  t('83105511540', '83105511539.5000000000000000000001', 1, 30, 7);
-  t('83105511540', '83105511539.5000000000000000000001', void 0, 30, 8);
+  t('83105511540', '83105511539.5', 1, 4);
+  t('83105511539', '83105511539.499999999999999999999999999999', 1, 4);
+  t('83105511539', '83105511539.5', '1', 5);
+  t('83105511540', '83105511539.5000000000000000000001', 1, 5);
+
+  Decimal.precision = 3;
+
+  t('83105511540', '83105511539.5', new Decimal(1), 4);
+  t('83105511539', '83105511539.499999999999999999999999999999', 1, 4);
+  t('83105511539', '83105511539.5', new Decimal('1'), 5);
+  t('83105511540', '83105511539.5000000000000000000001', 1, 5);
+
+  Decimal.precision = 20;
+
+  t('83105511540', '83105511539.5', -1, 4);
+  t('83105511539', '83105511539.499999999999999999999999999999', -1, 4);
+  t('83105511539', '83105511539.5', '-1', 5);
+  t('83105511540', '83105511539.5000000000000000000001', -1, 5);
+
+  t('-83105511540', '-83105511539.5', new Decimal(-1), 4);
+  t('-83105511539', '-83105511539.499999999999999999999999999999', 1, 4);
+  t('-83105511539', '-83105511539.5', new Decimal('-1'), 5);
+  t('-83105511540', '-83105511539.5000000000000000000001', -1, 5);
+
+  t('83105511540', '83105511539.5', 1, 0);
+  t('83105511539', '83105511539.5', 1, 1);
+  t('83105511540', '83105511539.5', 1, 2);
+  t('83105511539', '83105511539.5', 1, 3);
+  t('83105511540', '83105511539.5', 1, 4);
+  t('83105511539', '83105511539.5', 1, 5);
+  t('83105511540', '83105511539.5', 1, 6);
+  t('83105511540', '83105511539.5', 1, 7);
+  t('83105511539', '83105511539.5', 1, 8);
+  t('83105511539', '83105511539.499999999999999999999999999999', void 0, 0);
+  t('83105511539', '83105511539.499999999999999999999999999999', 1, 1);
+  t('83105511539', '83105511539.499999999999999999999999999999', void 0, 2);
+  t('83105511539', '83105511539.499999999999999999999999999999', 1, 3);
+  t('83105511539', '83105511539.499999999999999999999999999999', void 0, 4);
+  t('83105511539', '83105511539.499999999999999999999999999999', 1, 5);
+  t('83105511539', '83105511539.499999999999999999999999999999', void 0, 6);
+  t('83105511539', '83105511539.499999999999999999999999999999', 1, 7);
+  t('83105511539', '83105511539.499999999999999999999999999999', void 0, 8);
+  t('83105511540', '83105511539.5000000000000000000001', void 0, 0);
+  t('83105511539', '83105511539.5000000000000000000001', 1, 1);
+  t('83105511540', '83105511539.5000000000000000000001', void 0, 2);
+  t('83105511539', '83105511539.5000000000000000000001', 1, 3);
+  t('83105511540', '83105511539.5000000000000000000001', void 0, 4);
+  t('83105511540', '83105511539.5000000000000000000001', 1, 5);
+  t('83105511540', '83105511539.5000000000000000000001', void 0, 6);
+  t('83105511540', '83105511539.5000000000000000000001', 1, 7);
+  t('83105511540', '83105511539.5000000000000000000001', void 0, 8);
 
   Decimal.rounding = 0;
-  t('83105511540', '83105511539.5', void 0, 11);
+  t('83105511540', '83105511539.5');
 
   Decimal.rounding = 1;
-  t('83105511539', '83105511539.5', void 0, 11);
+  t('83105511539', '83105511539.5');
+
+  t('3847570', '3847561.00000749', 10, 0);
+  t('42840000000000000', '42835000000000001', '1e+13', 0);
+  t('42830000000000000', '42835000000000001', '1e+13', 1);
+  t('42840000000000000', '42835000000000000.0002', '1e+13', 0);
+  t('42830000000000000', '42835000000000000.0002', '1e+13', 1);
+
+  t('500', '449.999', 100, 0);
+  t('400', '449.999', 100, 1);
+  t('500', '449.999', 100, 2);
+  t('400', '449.999', 100, 3);
+  t('400', '449.999', 100, 4);
+  t('400', '449.999', 100, 5);
+  t('400', '449.999', 100, 6);
+  t('400', '449.999', 100, 7);
+  t('400', '449.999', 100, 8);
+
+  t('-500', '-449.999', 100, 0);
+  t('-400', '-449.999', 100, 1);
+  t('-400', '-449.999', 100, 2);
+  t('-500', '-449.999', 100, 3);
+  t('-400', '-449.999', 100, 4);
+  t('-400', '-449.999', 100, 5);
+  t('-400', '-449.999', 100, 6);
+  t('-400', '-449.999', 100, 7);
+  t('-400', '-449.999', 100, 8);
+
+  t('500', '450', 100, 0);
+  t('400', '450', 100, 1);
+  t('500', '450', 100, 2);
+  t('400', '450', 100, 3);
+  t('500', '450', 100, 4);
+  t('400', '450', 100, 5);
+  t('400', '450', 100, 6);
+  t('500', '450', 100, 7);
+  t('400', '450', 100, 8);
+
+  t('-500', '-450', 100, 0);
+  t('-400', '-450', 100, 1);
+  t('-400', '-450', 100, 2);
+  t('-500', '-450', 100, 3);
+  t('-500', '-450', 100, 4);
+  t('-400', '-450', 100, 5);
+  t('-400', '-450', 100, 6);
+  t('-400', '-450', 100, 7);
+  t('-500', '-450', 100, 8);
 
-  t('3847560', '3847561.00000749', 10, 11, 0);
-  t('42840000000000000', '42835000000000001', '1e+13', 2, 0);
-  t('42840000000000000', '42835000000000001', '1e+13', 2, 1);
-  t('42840000000000000', '42835000000000000.0002', '1e+13', 200, 0);
-  t('42840000000000000', '42835000000000000.0002', '1e+13', 200, 1);
+  Decimal.rounding = 0;
+  t('500', '450.001', 100);
+  Decimal.rounding = 1;
+  t('400', '450.001', 100);
+  Decimal.rounding = 2;
+  t('500', '450.001', 100);
+  Decimal.rounding = 3;
+  t('400', '450.001', 100);
+  Decimal.rounding = 4;
+  t('500', '450.001', 100);
+  Decimal.rounding = 5;
+  t('500', '450.001', 100);
+  Decimal.rounding = 6;
+  t('500', '450.001', 100);
+  Decimal.rounding = 7;
+  t('500', '450.001', 100);
+  Decimal.rounding = 8;
+  t('500', '450.001', 100);
+
+  Decimal.rounding = 0;
+  t('-500', '-450.001', 100);
+  Decimal.rounding = 1;
+  t('-400', '-450.001', 100);
+  Decimal.rounding = 2;
+  t('-400', '-450.001', 100);
+  Decimal.rounding = 3;
+  t('-500', '-450.001', 100);
+  Decimal.rounding = 4;
+  t('-500', '-450.001', 100);
+  Decimal.rounding = 5;
+  t('-500', '-450.001', 100);
+  Decimal.rounding = 6;
+  t('-500', '-450.001', 100);
+  Decimal.rounding = 7;
+  t('-500', '-450.001', 100);
+  Decimal.rounding = 8;
+  t('-500', '-450.001', 100);
 });