diff --git a/repl/lib_standard.c b/repl/lib_standard.c
index 8d35f50..1c261b1 100644
--- a/repl/lib_standard.c
+++ b/repl/lib_standard.c
@@ -706,6 +706,7 @@ static int nativeSin(Toy_Interpreter* interpreter, Toy_LiteralArray* arguments)
 
 	//cleanup
 	Toy_freeLiteral(resultLiteral);
+	Toy_freeLiteral(valueLiteral);
 
 	return 1;
 }
@@ -741,9 +742,9 @@ static int nativeCos(Toy_Interpreter* interpreter, Toy_LiteralArray* arguments)
 	float power = value;
 	int sign = 1;
 
-	for (int n = 1; n <= 10; n += 2) {
-        result += sign * power / n;
-        power = power * value * value;
+	for (int n = 0; n <= 10; n += 2) {
+        result += sign * power;
+        power = power * value * value / ((n + 1) * (n + 2));
         sign = -sign;
     }
 
@@ -753,6 +754,7 @@ static int nativeCos(Toy_Interpreter* interpreter, Toy_LiteralArray* arguments)
 
 	//cleanup
 	Toy_freeLiteral(resultLiteral);
+	Toy_freeLiteral(valueLiteral);
 
 	return 1;
 }
diff --git a/test/scripts/lib/standard.toy b/test/scripts/lib/standard.toy
index 4233bd3..c068468 100644
--- a/test/scripts/lib/standard.toy
+++ b/test/scripts/lib/standard.toy
@@ -143,8 +143,8 @@ import standard;
 	assert clamp(0.0, 1.0, 5.0) == 1, "clamp(0.0, 1.0, 5.0) failed";
 	assert clamp(10.0, 1.0, 5.0) == 5, "clamp(10.0, 1.0, 5.0) failed";
 
-	// assert typeof clamp(10, 1, 5) == int, "typeof clamp(10, 1, 5) == int failed";
-	// assert typeof clamp(10.0, 1, 5) == int, "typeof clamp(10.0, 1, 5) == int failed";
+	assert typeof clamp(10, 1, 5) == int, "typeof clamp(10, 1, 5) == int failed";
+	assert typeof clamp(10.0, 1, 5) == int, "typeof clamp(10.0, 1, 5) == int failed";
 	assert typeof clamp(10, 1, 5.0) == float, "typeof clamp(10, 1, 5.0) == float failed";
 }