diff --git a/lv_themes/lv_themes.mk b/lv_themes/lv_themes.mk
index 7e3b2a29cc..4b8c55a3e2 100644
--- a/lv_themes/lv_themes.mk
+++ b/lv_themes/lv_themes.mk
@@ -5,6 +5,7 @@ CSRCS += lv_theme_night.c
 CSRCS += lv_theme_templ.c
 CSRCS += lv_theme_zen.c
 CSRCS += lv_theme_material.c
+CSRCS += lv_theme_mono.c
 
 
 DEPPATH += --dep-path lvgl/lv_themes