diff --git a/DESCRIPTION b/DESCRIPTION
index e422614..2479d3e 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: xfun
 Type: Package
 Title: Supporting Functions for Packages Maintained by 'Yihui Xie'
-Version: 0.46.7
+Version: 0.46.8
 Authors@R: c(
   person("Yihui", "Xie", role = c("aut", "cre", "cph"), email = "xie@yihui.name", comment = c(ORCID = "0000-0003-0645-5666")),
   person("Wush", "Wu", role = "ctb"),
@@ -13,6 +13,7 @@ Authors@R: c(
   person()
   )
 Description: Miscellaneous functions commonly used in other packages maintained by 'Yihui Xie'.
+Depends: R (>= 3.2.0)
 Imports: grDevices, stats, tools
 Suggests: 
     testit,
diff --git a/R/zzz.R b/R/zzz.R
index 9e38985..489acd8 100644
--- a/R/zzz.R
+++ b/R/zzz.R
@@ -8,14 +8,6 @@ if (!has_fun('endsWith')) endsWith = function(x, s) {
   n = nchar(x)
   substring(x, n - nchar(s) + 1, n) == s
 }
-if (!has_fun('anyNA')) anyNA = function(x) any(is.na(x))
-if (!exists('trimws', baseenv(), inherits = FALSE)) trimws = function(x, which = 'both') {
-  r = c(both = '^\\s+|\\s+$', right = '\\s+$', left = '^\\s+')[which]
-  gsub(r, '', x)
-}
-if (!exists('file.size', baseenv(), inherits = FALSE)) file.size = function(...) {
-  file.info(...)$size
-}
 if (!has_fun('strrep')) strrep = function(x, times) {
   mapply(function(x, n) paste(rep(x, n), collapse = ''), x, times, USE.NAMES = FALSE)
 }