diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 6c471ab770..a9af7d94c1 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -10988,8 +10988,6 @@ static void f_has(typval_T *argvars, typval_T *rettv)
 #endif
     } else if (STRICMP(name, "syntax_items") == 0) {
       n = syntax_present(curwin);
-    } else if (STRICMP(name, "gui_running") == 0) {
-      n = ui_rgb_attached();
     }
   }
 
diff --git a/test/functional/ui/highlight_spec.lua b/test/functional/ui/highlight_spec.lua
index f9b112e464..6a89b0983d 100644
--- a/test/functional/ui/highlight_spec.lua
+++ b/test/functional/ui/highlight_spec.lua
@@ -14,15 +14,6 @@ describe('color scheme compatibility', function()
     request('vim_set_option', 't_Co', '88')
     eq('88', request('vim_eval', '&t_Co'))
   end)
-
-  it('emulates gui_running when a rgb UI is attached', function()
-    eq(0, request('vim_eval', 'has("gui_running")'))
-    local screen = Screen.new()
-    screen:attach()
-    eq(1, request('vim_eval', 'has("gui_running")'))
-    screen:detach()
-    eq(0, request('vim_eval', 'has("gui_running")'))
-  end)
 end)