diff --git a/include/locale b/include/locale
index 0d010020..38c68ec1 100644
--- a/include/locale
+++ b/include/locale
@@ -1585,7 +1585,7 @@ num_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base& __iob,
     this->__format_int(__fmt+1, __len, true, __iob.flags());
     const unsigned __nbuf = (numeric_limits<long long>::digits / 3)
                           + ((numeric_limits<long long>::digits % 3) != 0)
-                          + 1;
+                          + 2;
     char __nar[__nbuf];
 #ifdef _LIBCPP_LOCALE__L_EXTENSIONS
     int __nc = snprintf_l(__nar, sizeof(__nar), _LIBCPP_GET_C_LOCALE, __fmt, __v);
diff --git a/test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.inserters.arithmetic/minus1.pass b/test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.inserters.arithmetic/minus1.pass
new file mode 100644
index 00000000..27b8cfd8
--- /dev/null
+++ b/test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.inserters.arithmetic/minus1.pass
@@ -0,0 +1,84 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <ostream>
+
+// template <class charT, class traits = char_traits<charT> >
+//   class basic_ostream;
+
+// operator<<( int16_t val);
+// operator<<(uint16_t val);
+// operator<<( int32_t val);
+// operator<<(uint32_t val);
+// operator<<( int64_t val);
+// operator<<(uint64_t val);
+
+//  Testing to make sure that the max length values are correctly inserted
+
+#include <iostream>
+#include <sstream>
+#include <cassert>
+
+template <typename T>
+void test_octal(const char *expected)
+{
+    std::stringstream ss;
+    ss << std::oct << static_cast<T>(-1);
+    
+    assert(ss.str() == expected);
+}
+
+template <typename T>
+void test_dec(const char *expected)
+{
+    std::stringstream ss;
+    ss << std::dec << static_cast<T>(-1);
+    
+//  std::cout << ss.str() << " " << expected << std::endl;
+    assert(ss.str() == expected);
+}
+
+template <typename T>
+void test_hex(const char *expected)
+{
+    std::stringstream ss;
+    ss << std::hex << static_cast<T>(-1);
+    
+    std::string str = ss.str();
+    for (size_t i = 0; i < str.size(); ++i )
+        str[i] = std::toupper(str[i]);
+    
+    assert(str == expected);
+}
+
+int main(int argc, char* argv[])
+{
+    test_octal<uint16_t>(                "177777");
+    test_octal< int16_t>(                "177777");
+    test_octal<uint32_t>(           "37777777777");
+    test_octal< int32_t>(           "37777777777");
+    test_octal<uint64_t>("1777777777777777777777");
+    test_octal< int64_t>("1777777777777777777777");
+
+    test_dec<uint16_t>(               "65535");
+    test_dec< int16_t>(                  "-1");
+    test_dec<uint32_t>(          "4294967295");
+    test_dec< int32_t>(                  "-1");
+    test_dec<uint64_t>("18446744073709551615");
+    test_dec< int64_t>(                  "-1");
+
+    test_hex<uint16_t>(            "FFFF");
+    test_hex< int16_t>(            "FFFF");
+    test_hex<uint32_t>(        "FFFFFFFF");
+    test_hex< int32_t>(        "FFFFFFFF");
+    test_hex<uint64_t>("FFFFFFFFFFFFFFFF");
+    test_hex< int64_t>("FFFFFFFFFFFFFFFF");
+
+    return 0;
+}