diff --git a/src/DocumentMinifier.php b/src/DocumentMinifier.php
index bd33ea1..32e8400 100644
--- a/src/DocumentMinifier.php
+++ b/src/DocumentMinifier.php
@@ -248,7 +248,7 @@ private function extractZipTo(string $zippedDocumentPath, string $extractionDir,
             }
         }
         $zip = new \ZipArchive();
-        $openResult = $zip->open($zippedDocumentPath);
+        $openResult = $zip->open($zippedDocumentPath, \ZipArchive::CREATE);
         if ($openResult !== true) {
             throw new $exceptionClass(
                 "Exception when extracting document: Failed to open $zippedDocumentPath as a ZIP file."