diff --git a/R/common.R b/R/common.R
index 83b8e5d..8d5be80 100644
--- a/R/common.R
+++ b/R/common.R
@@ -74,7 +74,7 @@
 }
 
 highliteSubstrings <- function (string, substrings) {
-  what = paste0('(', paste0(substrings, collapse="|"), ')')
+  what = paste0('(', paste0(substrings, collapse="(?=\\W)|"), '(?=\\W))')
   with = '<b>\\1</b>'
   str_replace_all(string, what, with)
 }