diff --git a/tests/test-ewmh-wm_moveresize.lua b/tests/test-ewmh-wm_moveresize.lua
index 8cee77df0f..011ab03f24 100644
--- a/tests/test-ewmh-wm_moveresize.lua
+++ b/tests/test-ewmh-wm_moveresize.lua
@@ -1,5 +1,6 @@
 local test_client = require("_client")
 local placement = require("awful.placement")
+local unpack = unpack or table.unpack -- luacheck: globals unpack (compatibility with Lua 5.1)
 
 -- Testing utils
 local signals_of_interest = {
@@ -13,7 +14,7 @@ local function assert_signal(sig_name, asserts)
     local sig_data = signal_buffer[sig_name]
     assert(sig_data ~= nil, "expected signal: " .. sig_name)
     if asserts then
-        asserts(table.unpack(sig_data))
+        asserts(unpack(sig_data))
     end
     signal_buffer = {}
 end