diff --git a/lib/lexer.js b/lib/lexer.js
index ce3ebe5c..8e209b0c 100644
--- a/lib/lexer.js
+++ b/lib/lexer.js
@@ -623,8 +623,8 @@
   MULTI_DENT = /^(?:\n[^\n\S]*)+/;
   SIMPLESTR = /^'[^\\']*(?:\\.[^\\']*)*'/;
   JSTOKEN = /^`[^\\`]*(?:\\.[^\\`]*)*`/;
-  REGEX = /^\/(?!\s)[^[\/\n\\]*(?:(?:\\[\s\S]|\[[^\]\n\\]*(?:\\[\s\S][^\]\n\\]*)*])[^[\/\n\\]*)*\/[imgy]{0,4}(?![A-Za-z0-9])/;
-  HEREGEX = /^\/{3}([\s\S]+?)\/{3}([imgy]{0,4})(?![A-Za-z])/;
+  REGEX = /^\/(?!\s)[^[\/\n\\]*(?:(?:\\[\s\S]|\[[^\]\n\\]*(?:\\[\s\S][^\]\n\\]*)*])[^[\/\n\\]*)*\/[imgy]{0,4}(?!\w)/;
+  HEREGEX = /^\/{3}([\s\S]+?)\/{3}([imgy]{0,4})(?!\w)/;
   HEREGEX_OMIT = /\s+(?:#.*)?/g;
   MULTILINER = /\n/g;
   HEREDOC_INDENT = /\n+([^\n\S]*)/g;
diff --git a/src/lexer.coffee b/src/lexer.coffee
index 592e4662..b651edbc 100644
--- a/src/lexer.coffee
+++ b/src/lexer.coffee
@@ -585,10 +585,10 @@ REGEX = /// ^
          ]
     ) [^ [ / \n \\ ]*
   )*
-  / [imgy]{0,4} (?![A-Za-z0-9])
+  / [imgy]{0,4} (?!\w)
 ///
 
-HEREGEX      = /^\/{3}([\s\S]+?)\/{3}([imgy]{0,4})(?![A-Za-z])/
+HEREGEX      = /^\/{3}([\s\S]+?)\/{3}([imgy]{0,4})(?!\w)/
 
 HEREGEX_OMIT = /\s+(?:#.*)?/g