diff --git a/tool/update-bundled_gems.rb b/tool/update-bundled_gems.rb
index 2842516cac..e20566546b 100755
--- a/tool/update-bundled_gems.rb
+++ b/tool/update-bundled_gems.rb
@@ -22,7 +22,10 @@ unless /^[^#]/ !~ (gem = $F[0])
     else
       uri = $F[2]
     end
-    date = gem.date if !date or gem.date && gem.date > date
+    if (!date or gem.date && gem.date > date) and gem.date.to_i != 315_619_200
+      # DEFAULT_SOURCE_DATE_EPOCH is meaningless
+      date = gem.date
+    end
     if $F[3]
       if $F[3].include?($F[1])
         $F[3][$F[1]] = gem.version.to_s