diff --git a/include/xwayland/xwm.h b/include/xwayland/xwm.h
index d12eb681..24549644 100644
--- a/include/xwayland/xwm.h
+++ b/include/xwayland/xwm.h
@@ -86,7 +86,7 @@ enum atom_name {
 	ATOM_LAST // keep last
 };
 
-extern const char *atom_map[ATOM_LAST];
+extern const char *const atom_map[ATOM_LAST];
 
 struct wlr_xwm {
 	struct wlr_xwayland *xwayland;
diff --git a/xwayland/xwm.c b/xwayland/xwm.c
index cfc192f5..6ddc10d2 100644
--- a/xwayland/xwm.c
+++ b/xwayland/xwm.c
@@ -18,7 +18,7 @@
 #include "util/signal.h"
 #include "xwayland/xwm.h"
 
-const char *atom_map[ATOM_LAST] = {
+const char *const atom_map[ATOM_LAST] = {
 	[WL_SURFACE_ID] = "WL_SURFACE_ID",
 	[WM_DELETE_WINDOW] = "WM_DELETE_WINDOW",
 	[WM_PROTOCOLS] = "WM_PROTOCOLS",