--- a/mod_auth_ldap/mod_auth_ldap.lua	Wed Apr 24 11:00:17 2019 +0200
+++ b/mod_auth_ldap/mod_auth_ldap.lua	Mon Apr 29 00:04:16 2019 +0200
@@ -109,7 +109,11 @@
 	end
 elseif ldap_mode == "bind" then
 	local function test_password(userdn, password)
-		return not not lualdap.open_simple(ldap_server, userdn, password, ldap_tls);
+		local ok, err = lualdap.open_simple(ldap_server, userdn, password, ldap_tls);
+		if not ok then
+			log("debug", "ldap open_simple error: %s", err);
+		end
+		return not not ok;
 	end
 
 	function provider.test_password(username, password)