diff --git a/src/evalfunc.c b/src/evalfunc.c
index 4f0bb5c..91fbc67 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -4808,7 +4808,7 @@
     {
 	mode = tv_get_string_buf(&argvars[1], buf);
 	if (argvars[2].v_type != VAR_UNKNOWN)
-	    abbr = (int)tv_get_number(&argvars[2]);
+	    abbr = (int)tv_get_bool(&argvars[2]);
     }
 
     if (map_to_exists(name, mode, abbr))