diff --git a/lib/middleware/karma.js b/lib/middleware/karma.js
index 88e438112..cabeb2f81 100644
--- a/lib/middleware/karma.js
+++ b/lib/middleware/karma.js
@@ -193,7 +193,7 @@ function createKarmaMiddleware (
             } else {
               const scriptType = (SCRIPT_TYPE[fileType] || 'text/javascript')
               const crossOriginAttribute = includeCrossOriginAttribute ? 'crossorigin="anonymous"' : ''
-              if (scriptType === 'module') {
+              if (fileType === 'module') {
                 scriptTags.push(`<script onerror="throw 'Error loading ${filePath}'" type="${scriptType}" src="${filePath}" ${crossOriginAttribute}></script>`)
               } else {
                 scriptTags.push(`<script type="${scriptType}" src="${filePath}" ${crossOriginAttribute}></script>`)