diff --git a/R/find_rev.R b/R/find_rev.R
index dfefe1e7..3e784949 100644
--- a/R/find_rev.R
+++ b/R/find_rev.R
@@ -283,6 +283,16 @@ fetchpkgs  <- function(git_pkgs, archive_pkgs){
 #'   version 2.2.1 release, then use the Nix revision closest to that date, by setting
 #'   `r_ver = "3.1.0"`, which was the version of R current at the time. This
 #'   ensures that Nix builds a completely coherent environment.
+#'   By default, the nix shell will be configured with `"en_US.UTF-8"` for the
+#'   relevant locale variables (`LANG`, `LC_ALL`, `LC_TIME`, `LC_MONETARY`,
+#'   `LC_PAPER`). This is done to ensure locale reproducibility by default 
+#'   in Nix environments. If there are good reasons to not stick to the default,
+#'   you can set your preferred locale variables via 
+#'   `options(rix.nix_locale_variables = list(LANG = "de_CH.UTF-8", <...>)`
+#'   and the aforementioned locale variable names. However, you should use 
+#'   UTF-8 locales since we import the `glibcLocalesUtf8` set only, to not 
+#'   download the full set of locales and thereby keep the size reasonably
+#'   small.
 #' @export
 rix <- function(r_ver = "latest",
                 r_pkgs = NULL,
@@ -456,7 +466,7 @@ tex_pkgs)
   # to add it.
   generate_system_pkgs <- function(system_pkgs){
     sprintf('system_packages = builtins.attrValues {
-  inherit (pkgs) R glibcLocales %s;
+  inherit (pkgs) R glibcLocalesUtf8 %s;
 };
 ',
 get_system_pkgs(system_pkgs))
diff --git a/dev/build_envs.Rmd b/dev/build_envs.Rmd
index 526aacd0..12300850 100644
--- a/dev/build_envs.Rmd
+++ b/dev/build_envs.Rmd
@@ -367,6 +367,16 @@ you use another IDE, you can leave the "ide" argument blank:
 #'   version 2.2.1 release, then use the Nix revision closest to that date, by setting
 #'   `r_ver = "3.1.0"`, which was the version of R current at the time. This
 #'   ensures that Nix builds a completely coherent environment.
+#'   By default, the nix shell will be configured with `"en_US.UTF-8"` for the
+#'   relevant locale variables (`LANG`, `LC_ALL`, `LC_TIME`, `LC_MONETARY`,
+#'   `LC_PAPER`). This is done to ensure locale reproducibility by default 
+#'   in Nix environments. If there are good reasons to not stick to the default,
+#'   you can set your preferred locale variables via 
+#'   `options(rix.nix_locale_variables = list(LANG = "de_CH.UTF-8", <...>)`
+#'   and the aforementioned locale variable names. However, you should use 
+#'   UTF-8 locales since we import the `glibcLocalesUtf8` set only, to not 
+#'   download the full set of locales and thereby keep the size reasonably
+#'   small.
 #' @export
 rix <- function(r_ver = "latest",
                 r_pkgs = NULL,
@@ -540,7 +550,7 @@ tex_pkgs)
   # to add it.
   generate_system_pkgs <- function(system_pkgs){
     sprintf('system_packages = builtins.attrValues {
-  inherit (pkgs) R glibcLocales %s;
+  inherit (pkgs) R glibcLocalesUtf8 %s;
 };
 ',
 get_system_pkgs(system_pkgs))
diff --git a/inst/extdata/default.nix b/inst/extdata/default.nix
index ad2eb9ae..4abcebf5 100644
--- a/inst/extdata/default.nix
+++ b/inst/extdata/default.nix
@@ -29,7 +29,7 @@ let
     };
   }) ];
   system_packages = builtins.attrValues {
-  inherit (pkgs) R glibcLocales ;
+  inherit (pkgs) R glibcLocalesUtf8 ;
 };
   in
   pkgs.mkShell {
diff --git a/man/rix.Rd b/man/rix.Rd
index 49425d15..c6e773a3 100644
--- a/man/rix.Rd
+++ b/man/rix.Rd
@@ -88,4 +88,14 @@ want to use an environment as it would have looked at the time of \code{{ggplot2
 version 2.2.1 release, then use the Nix revision closest to that date, by setting
 \code{r_ver = "3.1.0"}, which was the version of R current at the time. This
 ensures that Nix builds a completely coherent environment.
+By default, the nix shell will be configured with \code{"en_US.UTF-8"} for the
+relevant locale variables (\code{LANG}, \code{LC_ALL}, \code{LC_TIME}, \code{LC_MONETARY},
+\code{LC_PAPER}). This is done to ensure locale reproducibility by default
+in Nix environments. If there are good reasons to not stick to the default,
+you can set your preferred locale variables via
+\verb{options(rix.nix_locale_variables = list(LANG = "de_CH.UTF-8", <...>)}
+and the aforementioned locale variable names. However, you should use
+UTF-8 locales since we import the \code{glibcLocalesUtf8} set only, to not
+download the full set of locales and thereby keep the size reasonably
+small.
 }