diff --git a/src/proto/term.pro b/src/proto/term.pro
index 42405dd..333df92 100644
--- a/src/proto/term.pro
+++ b/src/proto/term.pro
@@ -76,4 +76,5 @@
 void swap_tcap(void);
 guicolor_T gui_get_color_cmn(char_u *name);
 guicolor_T gui_get_rgb_color_cmn(int r, int g, int b);
+void cterm_color2rgb(int nr, uint8_t *r, uint8_t *g, uint8_t *b, uint8_t *ansi_idx);
 /* vim: set ft=c : */