diff --git a/ext/mssql/php_mssql.c b/ext/mssql/php_mssql.c
index fbeaa60ef0c..d74f0829d91 100644
--- a/ext/mssql/php_mssql.c
+++ b/ext/mssql/php_mssql.c
@@ -243,7 +243,12 @@ PHP_INI_BEGIN()
 	STD_PHP_INI_ENTRY_EX("mssql.max_links",				"-1",	PHP_INI_SYSTEM,	OnUpdateLong,	max_links,					zend_mssql_globals,		mssql_globals,	display_link_numbers)
 	STD_PHP_INI_ENTRY_EX("mssql.min_error_severity",	"10",	PHP_INI_ALL,	OnUpdateLong,	cfg_min_error_severity,		zend_mssql_globals,		mssql_globals,	display_link_numbers)
 	STD_PHP_INI_ENTRY_EX("mssql.min_message_severity",	"10",	PHP_INI_ALL,	OnUpdateLong,	cfg_min_message_severity,	zend_mssql_globals,		mssql_globals,	display_link_numbers)
-	STD_PHP_INI_BOOLEAN("mssql.compatability_mode",		"0",	PHP_INI_ALL,	OnUpdateBool,	compatability_mode,			zend_mssql_globals,		mssql_globals)
+	/*
+	  mssql.compatAbility_mode (with typo) was used for relatively long time.
+	  Unless it is fixed the old version is also kept for compatibility reasons.
+	*/
+	STD_PHP_INI_BOOLEAN("mssql.compatability_mode",		"0",	PHP_INI_ALL,	OnUpdateBool,	compatibility_mode,			zend_mssql_globals,		mssql_globals)
+	STD_PHP_INI_BOOLEAN("mssql.compatibility_mode",		"0",	PHP_INI_ALL,	OnUpdateBool,	compatibility_mode,			zend_mssql_globals,		mssql_globals)
 	STD_PHP_INI_ENTRY_EX("mssql.connect_timeout",    	"5",	PHP_INI_ALL,	OnUpdateLong,	connect_timeout,			zend_mssql_globals,		mssql_globals,	display_link_numbers)
 	STD_PHP_INI_ENTRY_EX("mssql.timeout",      			"60",	PHP_INI_ALL,	OnUpdateLong,	timeout,					zend_mssql_globals,		mssql_globals,	display_link_numbers)
 	STD_PHP_INI_ENTRY_EX("mssql.textsize",   			"-1",	PHP_INI_ALL,	OnUpdateLong,	textsize,					zend_mssql_globals,		mssql_globals,	display_text_size)
@@ -415,12 +420,12 @@ static void _mssql_bind_hash_dtor(void *data)
 */
 static PHP_GINIT_FUNCTION(mssql)
 {
-	long compatability_mode;
+	long compatibility_mode;
 
 	mssql_globals->num_persistent = 0;
 	mssql_globals->get_column_content = php_mssql_get_column_content_with_type;
-	if (cfg_get_long("mssql.compatability_mode", &compatability_mode) == SUCCESS) {
-		if (compatability_mode) {
+	if (cfg_get_long("mssql.compatibility_mode", &compatibility_mode) == SUCCESS) {
+		if (compatibility_mode) {
 			mssql_globals->get_column_content = php_mssql_get_column_content_without_type;	
 		}
 	}
diff --git a/ext/mssql/php_mssql.h b/ext/mssql/php_mssql.h
index b73c8420462..2b7d3e19c3a 100644
--- a/ext/mssql/php_mssql.h
+++ b/ext/mssql/php_mssql.h
@@ -166,7 +166,7 @@ ZEND_BEGIN_MODULE_GLOBALS(mssql)
 	long min_error_severity, min_message_severity;
 	long cfg_min_error_severity, cfg_min_message_severity;
 	long connect_timeout, timeout;
-	zend_bool compatability_mode;
+	zend_bool compatibility_mode;
 	void (*get_column_content)(mssql_link *mssql_ptr,int offset,zval *result,int column_type  TSRMLS_DC);
 	long textsize, textlimit, batchsize;
 	zend_bool datetimeconvert;
diff --git a/php.ini-development b/php.ini-development
index 05d1a9346e8..3c53ffd5002 100644
--- a/php.ini-development
+++ b/php.ini-development
@@ -1642,7 +1642,7 @@ mssql.min_error_severity = 10
 mssql.min_message_severity = 10
 
 ; Compatibility mode with old versions of PHP 3.0.
-mssql.compatability_mode = Off
+mssql.compatibility_mode = Off
 
 ; Connect timeout
 ;mssql.connect_timeout = 5
diff --git a/php.ini-production b/php.ini-production
index 21dbe432f77..91b55d614cd 100644
--- a/php.ini-production
+++ b/php.ini-production
@@ -1643,7 +1643,7 @@ mssql.min_error_severity = 10
 mssql.min_message_severity = 10
 
 ; Compatibility mode with old versions of PHP 3.0.
-mssql.compatability_mode = Off
+mssql.compatibility_mode = Off
 
 ; Connect timeout
 ;mssql.connect_timeout = 5