diff --git a/src/structs.h b/src/structs.h
index 4488bf8..f918442 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -92,8 +92,7 @@
 # ifdef FEAT_XCLIPBOARD
 #  include <X11/Intrinsic.h>
 # endif
-# define guicolor_T long_u		/* avoid error in prototypes and
-					 * make FEAT_TERMGUICOLORS work */
+# define guicolor_T long
 # define INVALCOLOR ((guicolor_T)0x1ffffff)
 #endif
 
@@ -929,8 +928,8 @@
 	    short_u	    fg_color;	/* foreground color number */
 	    short_u	    bg_color;	/* background color number */
 # ifdef FEAT_TERMGUICOLORS
-	    long_u	    fg_rgb;	/* foreground color RGB */
-	    long_u	    bg_rgb;	/* background color RGB */
+	    guicolor_T	    fg_rgb;	/* foreground color RGB */
+	    guicolor_T	    bg_rgb;	/* background color RGB */
 # endif
 	} cterm;
 # ifdef FEAT_GUI