diff --git a/htdocs/install/database.php b/htdocs/install/database.php
index 6b8528ea861..d3bd5168664 100644
--- a/htdocs/install/database.php
+++ b/htdocs/install/database.php
@@ -22,7 +22,7 @@
 
 include_once("./inc.php");
 
-$setuplang=$_POST["selectlang"];
+$setuplang=isset($_POST["selectlang"])?$_POST["selectlang"]:$langcode;
 $langs->defaultlang=$setuplang;
 $langs->load("install");
 
diff --git a/htdocs/install/etape1.php b/htdocs/install/etape1.php
index d1ad05514dc..036f33aeccb 100644
--- a/htdocs/install/etape1.php
+++ b/htdocs/install/etape1.php
@@ -31,7 +31,7 @@
 
 include_once("./inc.php");
 
-$setuplang=$_POST["selectlang"];
+$setuplang=isset($_POST["selectlang"])?$_POST["selectlang"]:$langcode;
 $langs->defaultlang=$setuplang;
 $langs->load("install");
 
diff --git a/htdocs/install/etape2.php b/htdocs/install/etape2.php
index e7aa01d16e9..e74abdf59ff 100644
--- a/htdocs/install/etape2.php
+++ b/htdocs/install/etape2.php
@@ -22,7 +22,7 @@
  */
 include_once("./inc.php");
 
-$setuplang=$_POST["selectlang"];
+$setuplang=isset($_POST["selectlang"])?$_POST["selectlang"]:$langcode;
 $langs->defaultlang=$setuplang;
 $langs->load("install");
 
diff --git a/htdocs/install/etape4.php b/htdocs/install/etape4.php
index e6834c801f0..6a12bd42f45 100644
--- a/htdocs/install/etape4.php
+++ b/htdocs/install/etape4.php
@@ -23,7 +23,7 @@
  */
 include_once("./inc.php");
 
-$setuplang=$_POST["selectlang"];
+$setuplang=isset($_POST["selectlang"])?$_POST["selectlang"]:$langcode;
 $langs->defaultlang=$setuplang;
 $langs->load("install");
 
diff --git a/htdocs/install/etape5.php b/htdocs/install/etape5.php
index 33c568e4bc6..3e2644df125 100644
--- a/htdocs/install/etape5.php
+++ b/htdocs/install/etape5.php
@@ -30,7 +30,7 @@
 
 include_once("./inc.php");
 
-$setuplang=$_POST["selectlang"];
+$setuplang=isset($_POST["selectlang"])?$_POST["selectlang"]:$langcode;
 $langs->defaultlang=$setuplang;
 $langs->load("install");
 
diff --git a/htdocs/install/fileconf.php b/htdocs/install/fileconf.php
index 34732dfcf77..fd08dd79c0d 100644
--- a/htdocs/install/fileconf.php
+++ b/htdocs/install/fileconf.php
@@ -31,7 +31,7 @@
 
 include_once("./inc.php");
 
-$setuplang=$_POST["selectlang"];
+$setuplang=isset($_POST["selectlang"])?$_POST["selectlang"]:$langcode;
 $langs->defaultlang=$setuplang;
 $langs->load("install");
 
diff --git a/htdocs/install/licence.php b/htdocs/install/licence.php
index cc0a7d42653..96af64f3f88 100644
--- a/htdocs/install/licence.php
+++ b/htdocs/install/licence.php
@@ -22,7 +22,7 @@
 
 include_once("./inc.php");
 
-$setuplang=$_POST["selectlang"];
+$setuplang=isset($_POST["selectlang"])?$_POST["selectlang"]:$langcode;
 $langs->defaultlang=$setuplang;
 $langs->load("install");