diff --git a/src/library/utils/R/citation.R b/src/library/utils/R/citation.R
index 5508d651813..16b9abda731 100644
--- a/src/library/utils/R/citation.R
+++ b/src/library/utils/R/citation.R
@@ -427,7 +427,7 @@ function(x,
     if(style == "R") return(.format_person_as_R_code(x))
 
     args <- c("given", "family", "email", "role", "comment")
-    include <- sapply(include, match.arg, args)
+    include <- vapply(include, match.arg, "", args)
 
     ## process defaults
     braces <- braces[args]
@@ -482,7 +482,7 @@ function(x,
 	paste(do.call(c, rval), collapse = " ")
     }
 
-    sapply(x, format_person1)
+    vapply(x, format_person1, "")
 }
 
 as.character.person <-
@@ -492,7 +492,7 @@ function(x, ...)
 toBibtex.person <-
 function(object, escape = FALSE, ...)
 {
-    object <- sapply(object, function(p) {
+    object <- vapply(object, function(p) {
          br <- if(is.null(p$family)) c("{", "}") else c("", "")
          s <- format(p, include = c("family", "given"),
                      braces = list(given = br, family = c("", ",")))
@@ -500,7 +500,7 @@ function(object, escape = FALSE, ...)
             (Encoding(s <- enc2utf8(s)) == "UTF-8"))
              tools::encoded_text_to_latex(s, "UTF-8")
          else s
-    })
+    }, "")
     paste(object[nzchar(object)], collapse = " and ")
 }
 
@@ -736,7 +736,7 @@ function(x, style = "text", .bibstyle = NULL,
         else if(is.character(macros))
             macros <- tools::loadRdMacros(macros,
                                           tools:::initialRdMacros())
-        sapply(.bibentry_expand_crossrefs(x),
+        vapply(.bibentry_expand_crossrefs(x),
                function(y) {
                    txt <- tools::toRd(y, style = .bibstyle)
                    ## <FIXME>
@@ -757,7 +757,8 @@ function(x, style = "text", .bibstyle = NULL,
                      outputEncoding = "UTF-8", ...)
                    paste(readLines(out, encoding = "UTF-8"),
                          collapse = "\n")
-               })
+               },
+               "")
     }
 
     format_as_citation <- function(x, msg) { # also (.., bibtex)
@@ -1121,7 +1122,7 @@ function(..., recursive = FALSE)
 toBibtex.bibentry <-
 function(object, escape = FALSE, ...)
 {
-    format_author <- function(author) paste(sapply(author, function(p) {
+    format_author <- function(author) paste(vapply(author, function(p) {
 	fnms <- p$family
 	only_given_or_family <-
             (is.null(fnms) || is.null(p$given)) &&
@@ -1132,7 +1133,7 @@ function(object, escape = FALSE, ...)
 	gbrc <- if(only_given_or_family) c("{", "}") else ""
         format(p, include = c("given", "family"),
                braces = list(given = gbrc, family = fbrc))
-    }), collapse = " and ")
+    }, ""), collapse = " and ")
 
     format_bibentry1 <- function(object) {
 	object <- unclass(object)[[1L]]
@@ -1143,8 +1144,10 @@ function(object, escape = FALSE, ...)
             object$editor <- format_author(object$editor)
 
         rval <- c(rval,
-                  sapply(names(object), function (n)
-                         paste0("  ", n, " = {", object[[n]], "},")),
+                  vapply(names(object),
+                         function (n)
+                             paste0("  ", n, " = {", object[[n]], "},"),
+                         ""),
                   "}", "")
         if(isTRUE(escape)) {
             rval <- enc2utf8(rval)
@@ -1535,7 +1538,7 @@ function(x)
         x <- .read_authors_at_R_field(x)
     header <- attr(x, "header")
     footer <- attr(x, "footer")
-    x <- sapply(x, .format_person_for_plain_author_spec)
+    x <- vapply(x, .format_person_for_plain_author_spec, "")
     ## Drop persons with irrelevant roles.
     x <- x[nzchar(x)]
     ## And format.
@@ -1622,7 +1625,7 @@ local({
 	}
 
 	authorList <- function(paper)
-	    sapply(paper$author, shortName)
+	    vapply(paper$author, shortName, "")
 
 	if (!missing(previous))
 	    cited <<- previous