diff --git a/src/session-child.c b/src/session-child.c
index 112daabe..2b3ee548 100644
--- a/src/session-child.c
+++ b/src/session-child.c
@@ -16,6 +16,7 @@
 #include <utmp.h>
 #include <utmpx.h>
 #include <sys/mman.h>
+#include <locale.h>
 
 #if HAVE_LIBAUDIT
 #include <libaudit.h>
@@ -294,6 +295,8 @@ session_child_run (int argc, char **argv)
     g_autofree gchar *xdisplay = read_string ();
     g_autoptr(XAuthority) x_authority = read_xauth ();
 
+    setlocale (LC_ALL, "");
+
     /* Setup PAM */
     struct pam_conv conversation = { pam_conv_cb, NULL };
     int result = pam_start (service, username, &conversation, &pam_handle);