diff --git a/mysql-test/suite/binlog/r/binlog_switch_inside_trans.result b/mysql-test/suite/binlog/r/binlog_switch_inside_trans.result
index 48b6dfa61d9..0819d4e778f 100644
--- a/mysql-test/suite/binlog/r/binlog_switch_inside_trans.result
+++ b/mysql-test/suite/binlog/r/binlog_switch_inside_trans.result
@@ -1,6 +1,5 @@
 set @save_binlog_format= @@global.binlog_format;
 set @save_binlog_dirct= @@global.binlog_direct_non_transactional_updates;
-set @save_sql_log_bin= @@global.sql_log_bin;
 create table t1 (a int) engine= myisam;
 create table t2 (a int) engine= innodb;
 SELECT @@session.binlog_format;
@@ -129,7 +128,7 @@ commit;
 begin;
 insert into t2 values (5);
 # Test that the global variable 'binlog_format' and
-# 'binlog_direct_non_transactional_updates' and 'sql_log_bin' are
+# 'binlog_direct_non_transactional_updates' are
 # writable inside a transaction.
 # Current session values are ROW, FALSE, TRUE respectively.
 SELECT @@global.binlog_format;
@@ -137,20 +136,15 @@ SELECT @@global.binlog_format;
 ROW
 set @@global.binlog_format= statement;
 set @@global.binlog_direct_non_transactional_updates= TRUE;
-set @@global.sql_log_bin= FALSE;
 SELECT @@global.binlog_format;
 @@global.binlog_format
 STATEMENT
 SELECT @@global.binlog_direct_non_transactional_updates;
 @@global.binlog_direct_non_transactional_updates
 1
-SELECT @@global.sql_log_bin;
-@@global.sql_log_bin
-0
 commit;
 set @@global.binlog_format= @save_binlog_format;
 set @@global.binlog_direct_non_transactional_updates= @save_binlog_dirct;
-set @@global.sql_log_bin= @save_sql_log_bin;
 create table t3(a int, b int) engine= innodb;
 create table t4(a int) engine= innodb;
 create table t5(a int) engine= innodb;
diff --git a/mysql-test/suite/binlog/t/binlog_grant.test b/mysql-test/suite/binlog/t/binlog_grant.test
index f0367b3aa79..0c9d9a45ec9 100644
--- a/mysql-test/suite/binlog/t/binlog_grant.test
+++ b/mysql-test/suite/binlog/t/binlog_grant.test
@@ -15,7 +15,7 @@ show grants for mysqltest_1@localhost;
 connect (plain,localhost,mysqltest_1,,test);
 connect (root,localhost,root,,test);
 
-# Testing setting both session and global SQL_LOG_BIN variable both as
+# Testing setting session SQL_LOG_BIN variable both as
 # root and as plain user.
 
 --echo **** Variable SQL_LOG_BIN ****
diff --git a/mysql-test/suite/binlog/t/binlog_switch_inside_trans.test b/mysql-test/suite/binlog/t/binlog_switch_inside_trans.test
index 06c5e78bd0e..a93cd44fa17 100644
--- a/mysql-test/suite/binlog/t/binlog_switch_inside_trans.test
+++ b/mysql-test/suite/binlog/t/binlog_switch_inside_trans.test
@@ -10,7 +10,6 @@ source include/have_binlog_format_row.inc;
 
 set @save_binlog_format= @@global.binlog_format;
 set @save_binlog_dirct= @@global.binlog_direct_non_transactional_updates;
-set @save_sql_log_bin= @@global.sql_log_bin;
 create table t1 (a int) engine= myisam;
 create table t2 (a int) engine= innodb;
 
@@ -117,21 +116,18 @@ commit;
 begin;
   insert into t2 values (5);
 --echo # Test that the global variable 'binlog_format' and
---echo # 'binlog_direct_non_transactional_updates' and 'sql_log_bin' are
+--echo # 'binlog_direct_non_transactional_updates' are
 --echo # writable inside a transaction.
 --echo # Current session values are ROW, FALSE, TRUE respectively.
   SELECT @@global.binlog_format;
   set @@global.binlog_format= statement;
   set @@global.binlog_direct_non_transactional_updates= TRUE;
-  set @@global.sql_log_bin= FALSE;
   SELECT @@global.binlog_format;
   SELECT @@global.binlog_direct_non_transactional_updates;
-  SELECT @@global.sql_log_bin;
 commit;
 
 set @@global.binlog_format= @save_binlog_format;
 set @@global.binlog_direct_non_transactional_updates= @save_binlog_dirct;
-set @@global.sql_log_bin= @save_sql_log_bin;
 
 create table t3(a int, b int) engine= innodb;
 create table t4(a int) engine= innodb;
diff --git a/mysql-test/suite/sys_vars/r/sql_log_bin_basic.result b/mysql-test/suite/sys_vars/r/sql_log_bin_basic.result
index 5e8fe4e02f7..7d9ef4f76ed 100644
--- a/mysql-test/suite/sys_vars/r/sql_log_bin_basic.result
+++ b/mysql-test/suite/sys_vars/r/sql_log_bin_basic.result
@@ -57,11 +57,16 @@ ERROR 42000: Variable 'sql_log_bin' can't be set to the value of '
 SET @@session.sql_log_bin = NO;
 ERROR 42000: Variable 'sql_log_bin' can't be set to the value of 'NO'
 '#-------------------FN_DYNVARS_156_05----------------------------#'
-SET @@global.sql_log_bin = 0;
 SELECT @@global.sql_log_bin;
 @@global.sql_log_bin
-0
+1
+SET @@global.sql_log_bin = 0;
+ERROR 42000: Variable 'sql_log_bin' can't be set to the value of '0'
+SELECT @@global.sql_log_bin;
+@@global.sql_log_bin
+1
 SET @@global.sql_log_bin = 1;
+ERROR 42000: Variable 'sql_log_bin' can't be set to the value of '1'
 '#----------------------FN_DYNVARS_156_06------------------------#'
 SELECT count(VARIABLE_VALUE) FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES WHERE VARIABLE_NAME='sql_log_bin';
 count(VARIABLE_VALUE)
diff --git a/mysql-test/suite/sys_vars/t/sql_log_bin_basic.test b/mysql-test/suite/sys_vars/t/sql_log_bin_basic.test
index 153a0be0b8f..1e697e72221 100644
--- a/mysql-test/suite/sys_vars/t/sql_log_bin_basic.test
+++ b/mysql-test/suite/sys_vars/t/sql_log_bin_basic.test
@@ -109,11 +109,15 @@ SET @@session.sql_log_bin = NO;
 
 --echo '#-------------------FN_DYNVARS_156_05----------------------------#'
 ########################################################################### 
-#       Test if accessing global sql_log_bin gives error                  #
+#       Test if setting global sql_log_bin gives error,                   #
+#       and there is no error on reading it.                              #
 ########################################################################### 
 
+SELECT @@global.sql_log_bin;
+--Error ER_WRONG_VALUE_FOR_VAR
 SET @@global.sql_log_bin = 0;
 SELECT @@global.sql_log_bin;
+--Error ER_WRONG_VALUE_FOR_VAR
 SET @@global.sql_log_bin = 1;
 
 --echo '#----------------------FN_DYNVARS_156_06------------------------#'
diff --git a/sql/sys_vars.cc b/sql/sys_vars.cc
index 3cb72480341..e826624b42f 100644
--- a/sql/sys_vars.cc
+++ b/sql/sys_vars.cc
@@ -2447,13 +2447,13 @@ static Sys_var_bit Sys_log_off(
 static bool fix_sql_log_bin_after_update(sys_var *self, THD *thd,
                                          enum_var_type type)
 {
-  if (type == OPT_SESSION)
-  {
-    if (thd->variables.sql_log_bin)
-      thd->variables.option_bits |= OPTION_BIN_LOG;
-    else
-      thd->variables.option_bits &= ~OPTION_BIN_LOG;
-  }
+  DBUG_ASSERT(type == OPT_SESSION);
+
+  if (thd->variables.sql_log_bin)
+    thd->variables.option_bits |= OPTION_BIN_LOG;
+  else
+    thd->variables.option_bits &= ~OPTION_BIN_LOG;
+
   return FALSE;
 }
 
@@ -2475,7 +2475,7 @@ static bool check_sql_log_bin(sys_var *self, THD *thd, set_var *var)
     return TRUE;
 
   if (var->type == OPT_GLOBAL)
-    return FALSE;
+    return TRUE;
 
   /* If in a stored function/trigger, it's too late to change sql_log_bin. */
   if (thd->in_sub_stmt)
@@ -2494,9 +2494,9 @@ static bool check_sql_log_bin(sys_var *self, THD *thd, set_var *var)
 }
 
 static Sys_var_mybool Sys_log_binlog(
-       "sql_log_bin", "sql_log_bin",
-       SESSION_VAR(sql_log_bin), NO_CMD_LINE,
-       DEFAULT(TRUE), NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(check_sql_log_bin),
+       "sql_log_bin", "Controls whether logging to the binary log is done",
+       SESSION_VAR(sql_log_bin), NO_CMD_LINE, DEFAULT(TRUE),
+       NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(check_sql_log_bin),
        ON_UPDATE(fix_sql_log_bin_after_update));
 
 static Sys_var_bit Sys_sql_warnings(