diff --git a/src/evalfunc.c b/src/evalfunc.c
index 42773e1..6f33016 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -10038,7 +10038,8 @@
 	    act = get_tv_string_chk(action_arg);
 	    if (act == NULL)
 		return;		/* type error; errmsg already given */
-	    if ((*act == 'a' || *act == 'r' || *act == ' ') && act[1] == NUL)
+	    if ((*act == 'a' || *act == 'r' || *act == ' ' || *act == 'f') &&
+		    act[1] == NUL)
 		action = *act;
 	    else
 		EMSG2(_(e_invact), act);