diff --git a/src/token_stream.mjs b/src/token_stream.mjs
index 7b319a0..cf29413 100644
--- a/src/token_stream.mjs
+++ b/src/token_stream.mjs
@@ -207,6 +207,6 @@ export class TokenStream {
 
   // Utility methods
   _isSpace(c) {
-    return /^\S\r\n/.test(c);
+    return /[^\S\r\n]/.test(c);
   }
 }