diff --git a/test/built-ins/Error/prototype/S15.11.3.1_A1_T1.js b/test/built-ins/Error/prototype/S15.11.3.1_A1_T1.js
index ecf6a6e088..336a11998a 100644
--- a/test/built-ins/Error/prototype/S15.11.3.1_A1_T1.js
+++ b/test/built-ins/Error/prototype/S15.11.3.1_A1_T1.js
@@ -5,6 +5,7 @@
 info: Error.prototype property has the attributes {DontDelete}
 es5id: 15.11.3.1_A1_T1
 description: Checking if deleting the Error.prototype property fails
+flags: [noStrict]
 ---*/
 
 var proto=Error.prototype;
diff --git a/test/built-ins/Error/prototype/S15.11.3.1_A2_T1.js b/test/built-ins/Error/prototype/S15.11.3.1_A2_T1.js
index 137c0c639e..29a397af74 100644
--- a/test/built-ins/Error/prototype/S15.11.3.1_A2_T1.js
+++ b/test/built-ins/Error/prototype/S15.11.3.1_A2_T1.js
@@ -27,9 +27,9 @@ if (Error.propertyIsEnumerable('prototype')) {
 
 //////////////////////////////////////////////////////////////////////////////
 // CHECK#2
-cout=0;
+var cout=0;
 
-for (p in Error){
+for (var p in Error){
   if (p==="prototype") cout++;
 }
 
diff --git a/test/built-ins/Error/prototype/S15.11.3.1_A3_T1.js b/test/built-ins/Error/prototype/S15.11.3.1_A3_T1.js
index b758aa0566..7b62671d7a 100644
--- a/test/built-ins/Error/prototype/S15.11.3.1_A3_T1.js
+++ b/test/built-ins/Error/prototype/S15.11.3.1_A3_T1.js
@@ -5,6 +5,7 @@
 info: Error.prototype property has the attributes {ReadOnly}
 es5id: 15.11.3.1_A3_T1
 description: Checking if varying the Error.prototype property fails
+flags: [noStrict]
 ---*/
 
 //////////////////////////////////////////////////////////////////////////////
diff --git a/test/built-ins/Error/prototype/S15.11.4_A2.js b/test/built-ins/Error/prototype/S15.11.4_A2.js
index 7c100386c0..8c1e40a121 100644
--- a/test/built-ins/Error/prototype/S15.11.4_A2.js
+++ b/test/built-ins/Error/prototype/S15.11.4_A2.js
@@ -12,7 +12,7 @@ description: >
 ---*/
 
 Error.prototype.toString=Object.prototype.toString;
-__tostr = Error.prototype.toString();
+var __tostr = Error.prototype.toString();
 
 //////////////////////////////////////////////////////////////////////////////
 //CHECK#1
diff --git a/test/built-ins/Error/prototype/S15.11.4_A3.js b/test/built-ins/Error/prototype/S15.11.4_A3.js
index dc5554e20a..8dbfec33b7 100644
--- a/test/built-ins/Error/prototype/S15.11.4_A3.js
+++ b/test/built-ins/Error/prototype/S15.11.4_A3.js
@@ -2,7 +2,7 @@
 // This code is governed by the BSD license found in the LICENSE file.
 
 /*---
-info: Since Error prototype object is not function it has not [[call]] method
+info: Since Error prototype object is not function it has no [[Call]] method
 es5id: 15.11.4_A3
 description: Checking if call of Error prototype as a function fails
 includes:
diff --git a/test/built-ins/Error/prototype/S15.11.4_A4.js b/test/built-ins/Error/prototype/S15.11.4_A4.js
index 28c206df61..ea86628300 100644
--- a/test/built-ins/Error/prototype/S15.11.4_A4.js
+++ b/test/built-ins/Error/prototype/S15.11.4_A4.js
@@ -2,7 +2,7 @@
 // This code is governed by the BSD license found in the LICENSE file.
 
 /*---
-info: Since Error prototype object is not function it has not [[create]] method
+info: Since Error prototype object is not function it has no [[Construct]] method
 es5id: 15.11.4_A4
 description: Checking if creating "new Error.prototype" fails
 includes:
@@ -13,8 +13,8 @@ includes:
 //////////////////////////////////////////////////////////////////////////////
 //CHECK#1
 try {
-	__instance = new Object.prototype;
-	$FAIL('#1: "__instance = new Object.prototype" lead to throwing exception');
+	var __instance = new Error.prototype;
+	$FAIL('#1: "var __instance = new Error.prototype" lead to throwing exception');
 } catch (e) {
     if (e instanceof Test262Error) throw e;
 }
diff --git a/test/built-ins/Error/prototype/constructor/S15.11.4.1_A1_T2.js b/test/built-ins/Error/prototype/constructor/S15.11.4.1_A1_T2.js
index c041d4dd84..e4e6b0f920 100644
--- a/test/built-ins/Error/prototype/constructor/S15.11.4.1_A1_T2.js
+++ b/test/built-ins/Error/prototype/constructor/S15.11.4.1_A1_T2.js
@@ -11,9 +11,9 @@ description: >
     checking its properties
 ---*/
 
-constr = Error.prototype.constructor;
+var constr = Error.prototype.constructor;
 
-err = new constr;
+var err = new constr;
 
 //////////////////////////////////////////////////////////////////////////////
 // CHECK#0
@@ -42,7 +42,7 @@ if (!(Error.prototype.isPrototypeOf(err))) {
 //////////////////////////////////////////////////////////////////////////////
 // CHECK#3
 Error.prototype.toString=Object.prototype.toString;
-to_string_result = '[object '+ 'Error' +']';
+var to_string_result = '[object '+ 'Error' +']';
 if (err.toString() !== to_string_result) {
 	$ERROR('#3: constr = Error.prototype.constructor; err = new constr; Error.prototype.toString=Object.prototype.toString; err.toString() === \'[object Error]\'. Actual: '+err.toString() );
 }