diff --git a/bin/preamble b/bin/preamble
index a563140..9bea3eb 100755
--- a/bin/preamble
+++ b/bin/preamble
@@ -8,7 +8,7 @@ fs.readFile("package.json", "utf8", function(error, text) {
   var json = JSON.parse(text);
   process.stdout.write("// " + (json.homepage || json.name)
       + " Version " + json.version + "."
-      + " Copyright " + (new Date).getFullYear()
+      + " Copyright " + (new Date(process.env.SOURCE_DATE_EPOCH ? (process.env.SOURCE_DATE_EPOCH * 1000) : new Date().getTime())).getFullYear()
       + " " + json.author.name + (/\.$/.test(json.author.name) ? "" : ".")
       + os.EOL);
 });