diff --git a/build/deb/install.forced.php.install b/build/deb/install.forced.php.install
index 105228e906c..518e1718143 100755
--- a/build/deb/install.forced.php.install
+++ b/build/deb/install.forced.php.install
@@ -12,5 +12,5 @@ $force_install_databaserootlogin='__SUPERUSERLOGIN__';
 $force_install_databaserootpass='__SUPERUSERPASSWORD__';
 $force_install_dolibarrlogin='admin';
 $force_install_nophpinfo='1';
-$force_install_lockinstall='1';
+$force_install_lockinstall='444';
 ?>
\ No newline at end of file
diff --git a/build/dmg/dolimamp/install.forced.php b/build/dmg/dolimamp/install.forced.php
index e5aa3c60065..74673452ceb 100644
--- a/build/dmg/dolimamp/install.forced.php
+++ b/build/dmg/dolimamp/install.forced.php
@@ -12,5 +12,5 @@ $force_install_databaserootlogin='root';
 $force_install_databaserootpass='root';
 $force_install_dolibarrlogin='admin';
 $force_install_nophpinfo='1';
-$force_install_lockinstall='1';
+$force_install_lockinstall='444';
 ?>
\ No newline at end of file
diff --git a/build/exe/doliwamp/install.forced.php.install b/build/exe/doliwamp/install.forced.php.install
index c024151ec0e..162dd21618f 100644
--- a/build/exe/doliwamp/install.forced.php.install
+++ b/build/exe/doliwamp/install.forced.php.install
@@ -12,5 +12,5 @@ $force_install_databaserootlogin='root';
 $force_install_databaserootpass='WAMPMYSQLNEWPASSWORD';
 $force_install_dolibarrlogin='admin';
 $force_install_nophpinfo='1';
-$force_install_lockinstall='1';
+$force_install_lockinstall='644';
 ?>
\ No newline at end of file
diff --git a/htdocs/install/etape5.php b/htdocs/install/etape5.php
index 37d95d4b131..860a0ffaa12 100644
--- a/htdocs/install/etape5.php
+++ b/htdocs/install/etape5.php
@@ -288,9 +288,10 @@ if ($_POST["action"] == "set")
 			$fp = @fopen($lockfile, "w");
 			if ($fp)
 			{
-				fwrite($fp, "This is a lock file to prevent use of install pages");
+                if ($force_install_lockinstall == 1) $force_install_lockinstall=444;    // For backward compatibility
+                fwrite($fp, "This is a lock file to prevent use of install pages (set with permission ".$force_install_lockinstall.")");
 				fclose($fp);
-				@chmod($lockfile, octdec(444));
+				@chmod($lockfile, octdec($force_install_lockinstall));
 				$createlock=1;
 			}
 		}
@@ -337,9 +338,10 @@ elseif (preg_match('/upgrade/i',$_POST["action"]))
 			$fp = @fopen($lockfile, "w");
 			if ($fp)
 			{
-				fwrite($fp, "This is a lock file to prevent use of install pages");
+                if ($force_install_lockinstall == 1) $force_install_lockinstall=444;    // For backward compatibility
+				fwrite($fp, "This is a lock file to prevent use of install pages (set with permission ".$force_install_lockinstall.")");
 				fclose($fp);
-				@chmod($lockfile, octdec(444));
+                @chmod($lockfile, octdec($force_install_lockinstall));
 				$createlock=1;
 			}
 		}