| Index: src/ia32/stub-cache-ia32.cc | 
| diff --git a/src/ia32/stub-cache-ia32.cc b/src/ia32/stub-cache-ia32.cc | 
| index fdb22acea056ba3ed4581ca34ec1e9032bf11041..5934149f08b69e31cbf12fbe1d548f029a8770c2 100644 | 
| --- a/src/ia32/stub-cache-ia32.cc | 
| +++ b/src/ia32/stub-cache-ia32.cc | 
| @@ -2204,8 +2204,9 @@ MaybeObject* CallStubCompiler::CompileCallConstant(Object* object, | 
| break; | 
|  | 
| case STRING_CHECK: | 
| -      if (!function->IsBuiltin()) { | 
| -        // Calling non-builtins with a value as receiver requires boxing. | 
| +      if (!function->IsBuiltin() && !function_info->strict_mode()) { | 
| +        // Calling non-strict non-builtins with a value as the receiver | 
| +        // requires boxing. | 
| __ jmp(&miss); | 
| } else { | 
| // Check that the object is a string or a symbol. | 
| @@ -2220,8 +2221,9 @@ MaybeObject* CallStubCompiler::CompileCallConstant(Object* object, | 
| break; | 
|  | 
| case NUMBER_CHECK: { | 
| -      if (!function->IsBuiltin()) { | 
| -        // Calling non-builtins with a value as receiver requires boxing. | 
| +      if (!function->IsBuiltin() && !function_info->strict_mode()) { | 
| +        // Calling non-strict non-builtins with a value as the receiver | 
| +        // requires boxing. | 
| __ jmp(&miss); | 
| } else { | 
| Label fast; | 
| @@ -2241,8 +2243,9 @@ MaybeObject* CallStubCompiler::CompileCallConstant(Object* object, | 
| } | 
|  | 
| case BOOLEAN_CHECK: { | 
| -      if (!function->IsBuiltin()) { | 
| -        // Calling non-builtins with a value as receiver requires boxing. | 
| +      if (!function->IsBuiltin() && !function_info->strict_mode()) { | 
| +        // Calling non-strict non-builtins with a value as the receiver | 
| +        // requires boxing. | 
| __ jmp(&miss); | 
| } else { | 
| Label fast; | 
|  |