diff --git a/spec/languages_spec.lua b/spec/languages_spec.lua
index 2264e9470..3d5b422f4 100644
--- a/spec/languages_spec.lua
+++ b/spec/languages_spec.lua
@@ -1,6 +1,13 @@
 SILE = require("core.sile")
 
 describe("Language module", function ()
+
+   it("should set env locale", function ()
+      SILE.call("language", { main = "tr" })
+      local syslang = os.getenv("LANG")
+      assert.is.equal("tr", syslang)
+   end)
+
    describe("Norwegian", function ()
       local hyphenate = SILE.showHyphenationPoints