diff --git a/test/built-ins/Math/sign/sign-specialVals.js b/test/built-ins/Math/sign/sign-specialVals.js
index 147842d31dfe0121f29774584ed1f45d3dc3bf69..0e63fe895f2b2410cf9c8393fb7627e10fe4f402 100644
--- a/test/built-ins/Math/sign/sign-specialVals.js
+++ b/test/built-ins/Math/sign/sign-specialVals.js
@@ -2,13 +2,19 @@
 // This code is governed by the license found in the LICENSE file.
 
 /*---
-description: Math.sign with special values
+description: >
+  Returns the sign of the x, indicating whether x is positive, negative or zero.
 es6id: 20.2.2.29
 ---*/
 
-assert.sameValue(Math.sign(NaN), Number.NaN,
-    "Math.sign produces incorrect output for NaN");
-assert.sameValue(1/Math.sign(-0), Number.NEGATIVE_INFINITY,
-    "Math.sign produces incorrect output for -0");
-assert.sameValue(1/Math.sign(0), Number.POSITIVE_INFINITY,
-    "Math.sign produces incorrect output for 0");
+assert.sameValue(Math.sign(NaN), NaN, "NaN");
+assert.sameValue(Math.sign(-0), -0, "-0");
+assert.sameValue(Math.sign(0), 0, "0");
+
+assert.sameValue(Math.sign(-0.000001), -1, "-0.000001");
+assert.sameValue(Math.sign(-1), -1, "-1");
+assert.sameValue(Math.sign(-Infinity), -1, "-Infinity");
+
+assert.sameValue(Math.sign(0.000001), 1, "0.000001");
+assert.sameValue(Math.sign(1), 1, "1");
+assert.sameValue(Math.sign(Infinity), 1, "Infinity");
diff --git a/test/built-ins/Math/sin/S15.8.2.16_A3.js b/test/built-ins/Math/sin/zero.js
similarity index 57%
rename from test/built-ins/Math/sin/S15.8.2.16_A3.js
rename to test/built-ins/Math/sin/zero.js
index e43b043112fdcb6ab72b428d00156c74a49aaf68..13380e0903d6159f4919c499d8a93cee495afef7 100644
--- a/test/built-ins/Math/sin/S15.8.2.16_A3.js
+++ b/test/built-ins/Math/sin/zero.js
@@ -2,9 +2,9 @@
 // This code is governed by the BSD license found in the LICENSE file.
 
 /*---
-info: If x is -0, Math.sin(x) is -0
 es5id: 15.8.2.16_A3
-description: Checking if Math.sin(-0) equals to -0
+description: Return arg if -0 or +0
 ---*/
 
-assert.sameValue(Math.sin(-0), -0);
+assert.sameValue(Math.sin(0), 0, "+0");
+assert.sameValue(Math.sin(-0), -0, "-0");
diff --git a/test/built-ins/Math/trunc/Math.trunc_Infinity.js b/test/built-ins/Math/trunc/Math.trunc_Infinity.js
index 6a9abb4272a05c8c2325da777200d06dd919fb9c..c90d127e1eed42cc637f8dc8409db26e0fc3ddcb 100644
--- a/test/built-ins/Math/trunc/Math.trunc_Infinity.js
+++ b/test/built-ins/Math/trunc/Math.trunc_Infinity.js
@@ -4,7 +4,8 @@
 /*---
 es6id: 20.2.2.35
 author: Ryan Lewis
-description: Math.trunc should return Infinity when called with Infinity.
+description: Return arg when called with Infinity or -Infinity.
 ---*/
 
-assert.sameValue(Math.trunc(.9), 0, 'Math.trunc(.9)');
+assert.sameValue(Math.trunc(Infinity), Infinity, 'Math.trunc(Infinity)');
+assert.sameValue(Math.trunc(-Infinity), -Infinity, 'Math.trunc(-Infinity)');