diff --git a/lib/whitespace.js b/lib/whitespace.js
index bfbe9ce..fb35530 100644
--- a/lib/whitespace.js
+++ b/lib/whitespace.js
@@ -148,8 +148,9 @@ module.exports = class Whitespace {
       scope: scopeDescriptor
     })
 
+    const markdownGrammars = ['source.gfm', 'text.md']
     const keepMarkdownLineBreakWhitespace =
-      grammarScopeName === ('source.gfm' || 'text.md') &&
+      markdownGrammars.includes(grammarScopeName) &&
       atom.config.get('whitespace.keepMarkdownLineBreakWhitespace')
 
     buffer.transact(() => {