diff --git a/tools/ei-demo-client.c b/tools/ei-demo-client.c
index 93351f9..c93bc54 100644
--- a/tools/ei-demo-client.c
+++ b/tools/ei-demo-client.c
@@ -55,7 +55,7 @@
 
 #include "src/util-macros.h"
 #include "src/util-mem.h"
-#include "src/util-memfile.h"
+#include "src/util-memmap.h"
 #include "src/util-color.h"
 #include "src/util-strings.h"
 #include "src/util-time.h"
@@ -84,6 +84,7 @@ colorprint(const char *format, ...)
 DEFINE_UNREF_CLEANUP_FUNC(xkb_context);
 DEFINE_UNREF_CLEANUP_FUNC(xkb_keymap);
 DEFINE_UNREF_CLEANUP_FUNC(xkb_state);
+DEFINE_UNREF_CLEANUP_FUNC(memmap);
 #endif
 
 static void
@@ -97,12 +98,13 @@ setup_xkb_keymap(struct ei_keymap *keymap)
 	if (!ctx)
 		return;
 
-	size_t sz = ei_keymap_get_size(keymap);
-	_cleanup_free_ char *buf = xalloc(sz + 1);
-	read(ei_keymap_get_fd(keymap), buf, sz);
-	buf[sz] = '\0';
+	_unref_(memmap) *memmap = memmap_new(ei_keymap_get_fd(keymap), ei_keymap_get_size(keymap));
+	if (!memmap) {
+		colorprint("Failed to mmap XKB keymap: %m\n");
+		return;
+	}
 
-	_unref_(xkb_keymap) *xkbmap = xkb_keymap_new_from_string(ctx, buf,
+	_unref_(xkb_keymap) *xkbmap = xkb_keymap_new_from_string(ctx, memmap_get_data(memmap),
 								 XKB_KEYMAP_FORMAT_TEXT_V1,
 								 XKB_KEYMAP_COMPILE_NO_FLAGS);
 	if (!xkbmap)