diff --git a/CHANGELOG.md b/CHANGELOG.md
index e3152acc..8fbe70ba 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -34,6 +34,13 @@
 ## Unreleased
 ### Added
 ### Changed
+
+* PGO helper scripts no longer set `LC_CTYPE=en_US.UTF-8`. But, note
+  that “full” PGO builds still **require** an UTF-8 locale; you need
+  to set one manually in your build script
+  (https://codeberg.org/dnkl/foot/issues/728).
+
+
 ### Deprecated
 ### Removed
 ### Fixed
diff --git a/INSTALL.md b/INSTALL.md
index 40b128e7..6fe8406b 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -281,6 +281,10 @@ reason there are a number of helper scripts available.
 scripts in the `pgo` directory to do a complete PGO build. This script
 is intended to be used when doing manual builds.
 
+Note that all “full” (which `auto` will prefer, if possible) PGO
+builds **require** `LC_CTYPE` to be set to an UTF-8 locale. This is
+**not** done automatically.
+
 Example:
 
 ```sh
diff --git a/PKGBUILD b/PKGBUILD
index 5c3666f9..c4c99282 100644
--- a/PKGBUILD
+++ b/PKGBUILD
@@ -1,4 +1,29 @@
-PGO=auto           # auto|none|partial|full-current-session|full-headless-sway|full-headless-cage
+# Select PGO (Performance Guided Optimizations) build type.
+#
+#  - auto: choose best available option
+#
+#  - none: disable PGO
+#
+#  - full-current-session: run a “full” PGO build in an existing
+#    Wayland session. This will pop up a foot window running a script
+#    that generates random terminal output.
+#
+#  - full-headless-sway: run a “full” PGO build inside a headless Sway
+#    instance. Requires Sway >= 1.7.
+#
+#  - full-headless-cage: run a “full” PGO build inside a headless Cage
+#    instance. Requires cage to be installed. Will generate lots of
+#    Cage warnings, but seems to procude a fully working (and well
+#    optimized) foot build.
+#
+#  - partial: run a “partial” PGO build. This requires neither a
+#    running Wayland session, nor an installed Wayland compositor.
+#
+# Note that “full-*” (which “auto” will prefer) requires an UTF-8
+# locale. Either make sure LC_CTYPE is set to an UTF-8 locale, or do a
+# “partial” PGO build (or disable PGO altoghether).
+
+PGO=auto
 
 pkgname=('foot-git' 'foot-terminfo-git')
 pkgver=1.9.1
diff --git a/pgo/full-inner.sh b/pgo/full-inner.sh
index 37cb2fb6..e6168081 100755
--- a/pgo/full-inner.sh
+++ b/pgo/full-inner.sh
@@ -15,10 +15,10 @@ rm -f "${blddir}"/pgo-ok
 # To ensure profiling data is generated in the build directory
 cd "${blddir}"
 
-LC_CTYPE=en_US.UTF-8 "${blddir}"/footclient --version
-LC_CTYPE=en_US.UTF-8 "${blddir}"/foot \
-        --config=/dev/null \
-        --term=xterm \
+"${blddir}"/footclient --version
+"${blddir}"/foot \
+           --config=/dev/null \
+           --term=xterm \
         sh -c "
           set -eux