diff --git a/spec/unit/optmath_spec.lua b/spec/unit/optmath_spec.lua
index 55610968f..d7f316cce 100644
--- a/spec/unit/optmath_spec.lua
+++ b/spec/unit/optmath_spec.lua
@@ -6,6 +6,34 @@ describe("Math module", function()
         Math = require("optmath")
     end)
 
+    describe("tmin", function()
+            it("should return nil on empty table", function()
+                assert.is_nil(Math.tmin({}))
+            end)
+            it("should get minimum element in table", function()
+                assert.are.same(5, Math.tmin({9,7,10,11,5,7}))
+            end)
+            it("should get minimum element in table using custom function", function()
+                assert.are.same(5,
+                                Math.tmin({"9","7","10","11","5","7"}, function(a,b)
+                                    return tonumber(a) > tonumber(b)
+                                end))
+            end)
+    end)
+    describe("tmax", function()
+            it("should return nil on empty table", function()
+                assert.is_nil(Math.tmin({}))
+            end)
+            it("should get maximum element in table", function()
+                assert.are.same(4, Math.tmax({9,7,10,11,5,7}))
+            end)
+            it("should get maximum element in table using custom function", function()
+                assert.are.same(4,
+                                Math.tmax({"9","7","10","11","5","7"}, function(a,b)
+                                    return tonumber(a) < tonumber(b)
+                                end))
+            end)
+    end)
     it("should round away from zero", function()
         assert.are.same(2, Math.roundAwayFromZero(1.5))
         assert.are.same(2, Math.roundAwayFromZero(1.4))