diff --git a/src/eval.c b/src/eval.c
index ca1c55b..87da4f3 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -1940,7 +1940,7 @@
 
     // avoid 'l' flag in 'cpoptions'
     save_cpo = p_cpo;
-    p_cpo = (char_u *)"";
+    p_cpo = empty_option;
     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
     if (regmatch.regprog != NULL)
     {
@@ -6200,8 +6200,14 @@
     if (p_cpo == empty_option)
 	p_cpo = save_cpo;
     else
+    {
 	// Darn, evaluating {sub} expression or {expr} changed the value.
+	// If it's still empty it was changed and restored, need to restore in
+	// the complicated way.
+	if (*p_cpo == NUL)
+	    set_option_value((char_u *)"cpo", 0L, save_cpo, 0);
 	free_string_option(save_cpo);
+    }
 
     return ret;
 }