diff --git a/R/util.R b/R/util.R
index 2de14b1..57e58b5 100644
--- a/R/util.R
+++ b/R/util.R
@@ -62,6 +62,7 @@
   x <- gsub("\\*", "\\\\*", x)
   x <- gsub("\\+", "\\\\+", x)
   x <- gsub("\\?", "\\\\?", x)
+  x <- gsub("\\|", "\\\\|", x)
   return(x)
 }