diff --git a/mkosi.build b/mkosi.build
index 6bbe8f3942..2231118da5 100755
--- a/mkosi.build
+++ b/mkosi.build
@@ -20,6 +20,7 @@
 # This is a build script for OS image generation using mkosi (https://github.com/systemd/mkosi).
 # Simply invoke "mkosi" in the project directory to build an OS image.
 
+export LC_CTYPE=C.UTF-8
 meson build
 ninja -C build all
 ninja -C build test