diff --git a/spec/unit/optmath_spec.lua b/spec/unit/optmath_spec.lua
new file mode 100644
index 000000000..b8e60aa97
--- /dev/null
+++ b/spec/unit/optmath_spec.lua
@@ -0,0 +1,32 @@
+describe("Math module", function()
+
+    setup(function()
+        require("commonrequire")
+        Math = require("optmath")
+    end)
+
+    it("should round away from zero", function()
+        assert.are.same(2, Math.roundAwayFromZero(1.5))
+        assert.are.same(2, Math.roundAwayFromZero(1.4))
+        assert.are.same(-2, Math.roundAwayFromZero(-1.4))
+        assert.are.same(1, Math.roundAwayFromZero(0.2))
+        assert.are.same(-1, Math.roundAwayFromZero(-0.2))
+    end)
+    it("should round", function()
+        assert.are.same(2, Math.round(1.5))
+        assert.are.same(1, Math.round(1.4))
+        assert.are.same(-1, Math.round(-1.4))
+        assert.are.same(0, Math.round(0.2))
+        assert.are.same(0, Math.round(-0.2))
+    end)
+    it("should determine odd or even", function()
+        assert.are.same("odd", Math.oddEven(1))
+        assert.are.same("even", Math.oddEven(2))
+        assert.are.same("odd", Math.oddEven(3))
+        assert.are.same("even", Math.oddEven(4))
+        assert.are.same("even", Math.oddEven(-4))
+        assert.are.same("odd", Math.oddEven(-3))
+        assert.are.same("even", Math.oddEven(0))
+    end)
+
+end)
diff --git a/spec/unit/util_spec.lua b/spec/unit/util_spec.lua
index 0184a83d5..b35df16d3 100644
--- a/spec/unit/util_spec.lua
+++ b/spec/unit/util_spec.lua
@@ -11,6 +11,8 @@ describe("util module", function()
         assert.is_equal(util.stripePunctuations("\"hello, world?\""), "hello, world")
         assert.is_equal(util.stripePunctuations("“你好“"), "你好")
         assert.is_equal(util.stripePunctuations("“你好?“"), "你好")
+        assert.is_equal(util.stripePunctuations(""), "")
+        assert.is_equal(util.stripePunctuations(nil), nil)
     end)
 
     it("should split string with patterns", function()