diff --git a/catalog/admin/includes/application_top.php b/catalog/admin/includes/application_top.php
index 0e823b214..2de27ec5e 100644
--- a/catalog/admin/includes/application_top.php
+++ b/catalog/admin/includes/application_top.php
@@ -164,7 +164,10 @@
   }
 
 // include the language translations
+  $_system_locale_numeric = setlocale(LC_NUMERIC, 0);
   require(DIR_WS_LANGUAGES . $language . '.php');
+  setlocale(LC_NUMERIC, $_system_locale_numeric); // Prevent LC_ALL from setting LC_NUMERIC which results in 1,0 float/decimal values instead of 1.0 (see bug #634)
+
   $current_page = basename($PHP_SELF);
   if (file_exists(DIR_WS_LANGUAGES . $language . '/' . $current_page)) {
     include(DIR_WS_LANGUAGES . $language . '/' . $current_page);
diff --git a/catalog/includes/application_top.php b/catalog/includes/application_top.php
index 38680594b..ec17acda4 100644
--- a/catalog/includes/application_top.php
+++ b/catalog/includes/application_top.php
@@ -278,7 +278,9 @@
   }
 
 // include the language translations
+  $_system_locale_numeric = setlocale(LC_NUMERIC, 0);
   require(DIR_WS_LANGUAGES . $language . '.php');
+  setlocale(LC_NUMERIC, $_system_locale_numeric); // Prevent LC_ALL from setting LC_NUMERIC which results in 1,0 float/decimal values instead of 1.0 (see bug #634)
 
 // currency
   if (!tep_session_is_registered('currency') || isset($HTTP_GET_VARS['currency']) || ( (USE_DEFAULT_LANGUAGE_CURRENCY == 'true') && (LANGUAGE_CURRENCY != $currency) ) ) {