diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 0f8c55e993..c44ce28bdf 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -15584,7 +15584,7 @@ static void setwinvar(typval_T *argvars, typval_T *rettv, int off)
         winvarname = xmalloc(STRLEN(varname) + 3);
         STRCPY(winvarname, "w:");
         STRCPY(winvarname + 2, varname);
-        set_var(winvarname, varp, TRUE);
+        set_var(winvarname, varp, true);
         xfree(winvarname);
       }
     }