diff --git a/.travis.yml b/.travis.yml
index ebe45b5748a..7699ca9c3ea 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -35,6 +35,7 @@ php:
 - '7.1'
 - '7.2'
 - '7.3'
+- '7.4'
 - nightly
 
 env:
@@ -67,6 +68,8 @@ matrix:
     env: DB=mariadb
   - php: '7.2'
     env: DB=mariadb
+  - php: '7.3'
+    env: DB=mariadb
   - php: '5.6'
     env: DB=postgresql
   - php: '7.0'
@@ -75,6 +78,8 @@ matrix:
     env: DB=postgresql
   - php: '7.2'
     env: DB=postgresql
+  - php: '7.3'
+    env: DB=postgresql
   - php: nightly
     env: DB=postgresql
 
@@ -125,7 +130,7 @@ install:
                         squizlabs/php_codesniffer ^3
   fi
   if [ "$TRAVIS_PHP_VERSION" = '5.6' ] || [ "$TRAVIS_PHP_VERSION" = '7.0' ] || [ "$TRAVIS_PHP_VERSION" = '7.1' ] \
-     [ "$TRAVIS_PHP_VERSION" = '7.2' ] || [ "$TRAVIS_PHP_VERSION" = '7.3' ]; then
+     [ "$TRAVIS_PHP_VERSION" = '7.2' ] || [ "$TRAVIS_PHP_VERSION" = '7.3' ] || [ "$TRAVIS_PHP_VERSION" = '7.4' ]; then
     composer -n require phpunit/phpunit ^5 \
                         jakub-onderka/php-parallel-lint ^0 \
                         jakub-onderka/php-console-highlighter ^0 \
@@ -248,7 +253,7 @@ before_script:
   # enable php-fpm
   - sudo cp ~/.phpenv/versions/$(phpenv version-name)/etc/php-fpm.conf.default ~/.phpenv/versions/$(phpenv version-name)/etc/php-fpm.conf
   - |
-    if [ "$TRAVIS_PHP_VERSION" = '7.0' ] || [ "$TRAVIS_PHP_VERSION" = '7.1' ] || [ "$TRAVIS_PHP_VERSION" = '7.2' ] || [ "$TRAVIS_PHP_VERSION" = '7.3' ] || [ "$TRAVIS_PHP_VERSION" = 'nightly' ]; then
+    if [ "$TRAVIS_PHP_VERSION" = '7.0' ] || [ "$TRAVIS_PHP_VERSION" = '7.1' ] || [ "$TRAVIS_PHP_VERSION" = '7.2' ] || [ "$TRAVIS_PHP_VERSION" = '7.3' ] || [ "$TRAVIS_PHP_VERSION" = '7.4' ] || [ "$TRAVIS_PHP_VERSION" = 'nightly' ]; then
       # Copy the included pool
       sudo cp ~/.phpenv/versions/$(phpenv version-name)/etc/php-fpm.d/www.conf.default ~/.phpenv/versions/$(phpenv version-name)/etc/php-fpm.d/www.conf
     fi
diff --git a/htdocs/core/lib/functions2.lib.php b/htdocs/core/lib/functions2.lib.php
index 0356ecc8b23..cc6fb31c1de 100644
--- a/htdocs/core/lib/functions2.lib.php
+++ b/htdocs/core/lib/functions2.lib.php
@@ -1347,7 +1347,7 @@ function hexbin($hexa)
     $strLength = dol_strlen($hexa);
     for ($i = 0; $i < $strLength; $i++)
     {
-        $bin .= str_pad(decbin(hexdec($hexa{$i})), 4, '0', STR_PAD_LEFT);
+        $bin .= str_pad(decbin(hexdec($hexa[$i])), 4, '0', STR_PAD_LEFT);
     }
     return $bin;
 }
diff --git a/htdocs/core/lib/json.lib.php b/htdocs/core/lib/json.lib.php
index 3ce9d871b7f..77b856e2d8e 100644
--- a/htdocs/core/lib/json.lib.php
+++ b/htdocs/core/lib/json.lib.php
@@ -286,6 +286,7 @@ function dol_json_decode($json, $assoc = false)
  */
 function _unval($val)
 {
+	$reg = array();
 	while (preg_match('/\\\u([0-9A-F]{2})([0-9A-F]{2})/i', $val, $reg))
 	{
 	    // single, escaped unicode character
@@ -313,7 +314,7 @@ function utf162utf8($utf16)
 	    return mb_convert_encoding($utf16, 'UTF-8', 'UTF-16');
 	}
 
-	$bytes = (ord($utf16{0}) << 8) | ord($utf16{1});
+	$bytes = (ord($utf16[0]) << 8) | ord($utf16[1]);
 
 	switch(true) {
     	case ((0x7F & $bytes) == $bytes):
@@ -352,7 +353,7 @@ function utf162utf8($utf16)
 function utf82utf16($utf8)
 {
 	// oh please oh please oh please oh please oh please
-	if(function_exists('mb_convert_encoding')) {
+	if (function_exists('mb_convert_encoding')) {
 	    return mb_convert_encoding($utf8, 'UTF-16', 'UTF-8');
 	}
 
@@ -365,12 +366,12 @@ function utf82utf16($utf8)
 		case 2:
 			// return a UTF-16 character from a 2-byte UTF-8 char
 			// see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
-			return chr(0x07 & (ord($utf8{0}) >> 2)) . chr((0xC0 & (ord($utf8{0}) << 6)) | (0x3F & ord($utf8{1})));
+			return chr(0x07 & (ord($utf8[0]) >> 2)) . chr((0xC0 & (ord($utf8[0]) << 6)) | (0x3F & ord($utf8[1])));
 
 		case 3:
 			// return a UTF-16 character from a 3-byte UTF-8 char
 			// see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
-			return chr((0xF0 & (ord($utf8{0}) << 4)) | (0x0F & (ord($utf8{1}) >> 2))) . chr((0xC0 & (ord($utf8{1}) << 6)) | (0x7F & ord($utf8{2})));
+			return chr((0xF0 & (ord($utf8[0]) << 4)) | (0x0F & (ord($utf8[1]) >> 2))) . chr((0xC0 & (ord($utf8[1]) << 6)) | (0x7F & ord($utf8[2])));
 	}
 
 	// ignoring UTF-32 for now, sorry