diff --git a/src/testdir/test_lua.vim b/src/testdir/test_lua.vim
index f6cdae1..89329ee 100644
--- a/src/testdir/test_lua.vim
+++ b/src/testdir/test_lua.vim
@@ -14,9 +14,17 @@
 
 " Depending on the lua version, the error messages are different.
 let s:luaver = split(split(systemlist('lua -v')[0], ' ')[1], '\.')
+if len(s:luaver) < 3
+  " Didn't get something that looks like a version, use _VERSION.
+  let s:luaver = split(split(luaeval('_VERSION'), ' ')[1], '\.')
+endif
 let s:major = str2nr(s:luaver[0])
 let s:minor = str2nr(s:luaver[1])
-let s:patch = str2nr(s:luaver[2])
+if len(s:luaver >= 3)
+  let s:patch = str2nr(s:luaver[2])
+else
+  let s:patch = 0
+endif
 let s:lua_53_or_later = 0
 let s:lua_543_or_later = 0
 if (s:major == 5 && s:minor >= 3) || s:major > 5