diff --git a/src/library/tools/R/Rd2HTML.R b/src/library/tools/R/Rd2HTML.R
index 2ee5df5ea7..ab09097fd5 100644
--- a/src/library/tools/R/Rd2HTML.R
+++ b/src/library/tools/R/Rd2HTML.R
@@ -1455,7 +1455,7 @@ function(dir)
         if(a) {
             ## URL regexp as in .DESCRIPTION_to_latex().  CRAN uses
             ##   <(URL: *)?((https?|ftp)://[^[:space:]]+)[[:space:]]*>
-            ##   ([^>\"?])((https?|ftp)://[[:alnum:]/.:@+\\_~%#?=&;,-]+[[:alnum:]/])
+            ##   ([[:space:]])((https?|ftp)://[[:alnum:]/.:@+\\_~%#?=&;,-]+[[:alnum:]/])
             ## (also used in toRd.citation().
             x <- trfm("&lt;(http://|ftp://|https://)([^[:space:],>]+)&gt;",
                       "<a href=\"\\1%s\">\\1\\2</a>",
diff --git a/src/library/tools/R/toHTML.R b/src/library/tools/R/toHTML.R
index d75a3aff36..11affb49b5 100644
--- a/src/library/tools/R/toHTML.R
+++ b/src/library/tools/R/toHTML.R
@@ -342,7 +342,7 @@ function(x, header = TRUE, ...)
             ## Need to ignore results of the above translation ...
             ## Regexp based on Perl HTML::TextToHTML, note that the dash
             ## must be last ...
-            s <- .gsub_with_transformed_matches("([^>\"?])((https?|ftp)://[[:alnum:]/.:@+\\_~%#?=&;,-]+[[:alnum:]/])",
+            s <- .gsub_with_transformed_matches("([[:space:]])((https?|ftp)://[[:alnum:]/.:@+\\_~%#?=&;,-]+[[:alnum:]/])",
                                                 "\\1<a href=\"%s\">\\2</a>",
                                                 s,
                                                 urlify,