diff --git a/big-integer/big-integer-tests.ts b/big-integer/big-integer-tests.ts
index 3b9fb8745..92633d287 100644
--- a/big-integer/big-integer-tests.ts
+++ b/big-integer/big-integer-tests.ts
@@ -4,6 +4,9 @@
 var noArgument = bigInt(),
     numberArgument = bigInt( 93 ),
     stringArgument = bigInt( "75643564363473453456342378564387956906736546456235345" ),
+    baseArgumentInt = bigInt( "101010", 2 ),
+    baseArgumentStr = bigInt( "101010", "2" ),
+    baseArgumentBi  = bigInt( "101010", bigInt( 2 ) ), 
     bigIntArgument = bigInt( noArgument );
 
 // method tests
@@ -111,4 +114,4 @@ isNumber = x.toJSNumber();
 
 isString = x.toString();
 
-isNumber = x.valueOf();
\ No newline at end of file
+isNumber = x.valueOf();
diff --git a/big-integer/big-integer.d.ts b/big-integer/big-integer.d.ts
index 633432e19..9e9127e83 100644
--- a/big-integer/big-integer.d.ts
+++ b/big-integer/big-integer.d.ts
@@ -214,7 +214,7 @@ interface BigIntegerStatic {
     /** Parse a Javascript number into a bigInt */
     ( number: number ): BigInteger;
     /** Parse a string into a bigInt */
-    ( string: string ): BigInteger;
+    ( string: string,  base?: string | number | BigInteger): BigInteger;
     /** no-op */
     ( bigInt: BigInteger ): BigInteger;
 }
@@ -223,4 +223,4 @@ declare var bigInt: BigIntegerStatic;
 
 declare module "big-integer" {
     export = bigInt;
-}
\ No newline at end of file
+}