diff --git a/double-conversion/bignum.h b/double-conversion/bignum.h
index 9d8563d..57e4230 100644
--- a/double-conversion/bignum.h
+++ b/double-conversion/bignum.h
@@ -49,7 +49,6 @@
 
   void AssignPowerUInt16(uint16_t base, int exponent);
 
-  void AddUInt16(uint16_t operand);
   void AddUInt64(uint64_t operand);
   void AddBignum(const Bignum& other);
   // Precondition: this >= other.
diff --git a/test/cctest/test-bignum.cc b/test/cctest/test-bignum.cc
index 38c151c..84c4a09 100644
--- a/test/cctest/test-bignum.cc
+++ b/test/cctest/test-bignum.cc
@@ -993,6 +993,7 @@
   other.AssignUInt16(2);
   other.ShiftLeft(500);
   CHECK_EQ(5, bignum.DivideModuloIntBignum(other));
+  CHECK(bignum.ToHexString(buffer, kBufferSize));
   CHECK_EQ("0", buffer);
 
   bignum.AssignUInt16(11);