diff --git a/BUILD_NUMBER b/.build_number
similarity index 100%
rename from BUILD_NUMBER
rename to .build_number
diff --git a/.gitattributes b/.gitattributes
index 9122eeb17b..fdf9d072f7 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,2 +1,2 @@
-BUILD_NUMBER	merge=merge-keep-ours
+.build_number	merge=merge-keep-ours
 
diff --git a/modules/gallery/helpers/gallery.php b/modules/gallery/helpers/gallery.php
index 7a60f56ace..ad9f40e89c 100644
--- a/modules/gallery/helpers/gallery.php
+++ b/modules/gallery/helpers/gallery.php
@@ -202,10 +202,10 @@ static function version_string() {
   }
 
   /**
-   * Return the contents of the BUILD_NUMBER file, which should be a single integer.
+   * Return the contents of the .build_number file, which should be a single integer.
    */
   static function build_number() {
-    $result = parse_ini_file(DOCROOT . "BUILD_NUMBER");
+    $result = parse_ini_file(DOCROOT . ".build_number");
     return $result["build_number"];
   }
 }
\ No newline at end of file