diff --git a/test/built-ins/Boolean/S15.6.1.1_A1_T5.js b/test/built-ins/Boolean/S15.6.1.1_A1_T5.js
index 2114e1995801d37470d54a862a4233753e59c452..e0fd8d8c7725f70c26a7c4d59de6b6a191c7e0b8 100644
--- a/test/built-ins/Boolean/S15.6.1.1_A1_T5.js
+++ b/test/built-ins/Boolean/S15.6.1.1_A1_T5.js
@@ -9,6 +9,8 @@ es5id: 15.6.1.1_A1_T5
 description: Used various assigning values to any variable as argument
 ---*/
 
+var x;
+
 //CHECK#1
 if( typeof Boolean(x=0) !== "boolean" ) {
   $ERROR('#1.1: typeof Boolean(x=0) should be "boolean", actual is "'+typeof Boolean(x=0)+'"');
diff --git a/test/built-ins/Boolean/prototype/S15.6.3.1_A2.js b/test/built-ins/Boolean/prototype/S15.6.3.1_A2.js
index f276ec5ccc112db70b8fae71325efb6dd7ca40a4..c834d39fd2d20bcf5f0af87ec96f9b9b945f42e0 100644
--- a/test/built-ins/Boolean/prototype/S15.6.3.1_A2.js
+++ b/test/built-ins/Boolean/prototype/S15.6.3.1_A2.js
@@ -5,6 +5,7 @@
 info: Boolean.prototype has the attribute ReadOnly
 es5id: 15.6.3.1_A2
 description: Checking if varying the Boolean.prototype property fails
+flags: [noStrict]
 ---*/
 
 // CHECK#1
diff --git a/test/built-ins/Boolean/prototype/S15.6.3.1_A3.js b/test/built-ins/Boolean/prototype/S15.6.3.1_A3.js
index 6163f75ec0669d882eb9cdb393811aec82db32d3..3decf9d4471a5b17202bf7a316308dcb60ddecf0 100644
--- a/test/built-ins/Boolean/prototype/S15.6.3.1_A3.js
+++ b/test/built-ins/Boolean/prototype/S15.6.3.1_A3.js
@@ -5,6 +5,7 @@
 info: Boolean.prototype has the attribute DontDelete
 es5id: 15.6.3.1_A3
 description: Checking if deleting the Boolean.prototype property fails
+flags: [noStrict]
 ---*/
 
 // CHECK#1