diff --git a/libstdc++-v3/include/bits/streambuf_iterator.h b/libstdc++-v3/include/bits/streambuf_iterator.h
index 32285a668fc..4527660e191 100644
--- a/libstdc++-v3/include/bits/streambuf_iterator.h
+++ b/libstdc++-v3/include/bits/streambuf_iterator.h
@@ -479,37 +479,59 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       __glibcxx_assert(__n > 0);
       __glibcxx_requires_cond(!__i._M_at_eof(),
-			      _M_message(__gnu_debug::__msg_inc_istreambuf)
-			      ._M_iterator(__i));
+			      _M_message(__gnu_debug::__msg_advance_oob)
+			      ._M_iterator(__i)
+			      ._M_integer(__n));
 
       typedef istreambuf_iterator<_CharT>		   __is_iterator_type;
       typedef typename __is_iterator_type::traits_type	   traits_type;
       typedef typename __is_iterator_type::streambuf_type  streambuf_type;
       typedef typename traits_type::int_type		   int_type;
+      typedef typename traits_type::off_type		   off_type;
+      typedef typename streambuf_type::pos_type		   pos_type;
       const int_type __eof = traits_type::eof();
+      const pos_type __npos = pos_type(off_type(-1));
 
       streambuf_type* __sb = __i._M_sbuf;
-      while (__n > 0)
-	{
       streamsize __size = __sb->egptr() - __sb->gptr();
-	  if (__size > __n)
-	    {
+      if (__size >= __n)
 	__sb->__safe_gbump(__n);
-	      break;
-	    }
-
+      else
+	{
+	  // Check for seekoff support.
+	  if (__sb->pubseekoff(0, ios_base::cur, ios_base::in) != __npos)
+	    __sb->pubseekoff(__n, ios_base::cur, ios_base::in);
+	  else
+	    {
+	      _GLIBCXX_DEBUG_ONLY(_Distance __n_orig = __n);
+	      for (;;)
+		{
 		  __sb->__safe_gbump(__size);
 		  __n -= __size;
+
+		  if (__n == 0)
+		    break;
+
 		  if (traits_type::eq_int_type(__sb->underflow(), __eof))
 		    {
-	      __glibcxx_requires_cond(__n == 0,
-				_M_message(__gnu_debug::__msg_inc_istreambuf)
-				._M_iterator(__i));
+		      __i._M_sbuf = 0;
 		      break;
 		    }
+
+		  __size = __sb->egptr() - __sb->gptr();
+		  if (__size > __n)
+		    __size = __n;
+		}
+
+	      _GLIBCXX_DEBUG_ONLY(__n = __n_orig);
+	    }
 	}
 
       __i._M_c = __eof;
+      __glibcxx_requires_cond(!__i._M_at_eof(),
+			      _M_message(__gnu_debug::__msg_advance_oob)
+			      ._M_iterator(__i)
+			      ._M_integer(__n));
     }
 
 /// @} group iterators
diff --git a/libstdc++-v3/testsuite/25_algorithms/advance/istreambuf_iterators/char/4_neg.cc b/libstdc++-v3/testsuite/25_algorithms/advance/istreambuf_iterators/char/4_neg.cc
new file mode 100644
index 00000000000..88ccaeff499
--- /dev/null
+++ b/libstdc++-v3/testsuite/25_algorithms/advance/istreambuf_iterators/char/4_neg.cc
@@ -0,0 +1,65 @@
+// { dg-require-fileio "" }
+// { dg-do run { xfail *-*-* } }
+// { dg-require-debug-mode "" }
+
+#include <iterator>
+#include <fstream>
+#include <algorithm>
+
+#include <testsuite_hooks.h>
+
+void test01()
+{
+  using namespace std;
+
+  typedef istreambuf_iterator<char> in_iterator_type;
+
+  unsigned found = 0;
+
+  {
+    ifstream fbuf("istream_unformatted-1.txt");
+
+    in_iterator_type beg(fbuf);
+    in_iterator_type end;
+
+    for (;;)
+      {
+	beg = find(beg, end, '1');
+	if (beg == end)
+	  break;
+
+	++found;
+	VERIFY( *beg == '1' );
+
+	advance(beg, 9);
+	VERIFY( *beg == '0' );
+      }
+  }
+
+  {
+    ifstream fbuf("istream_unformatted-1.txt");
+
+    in_iterator_type beg(fbuf);
+    in_iterator_type end;
+
+    beg = find(beg, end, '1');
+    VERIFY( beg != end );
+    VERIFY( *beg == '1' );
+
+    advance(beg, 9);
+    VERIFY( *beg == '0' );
+
+    unsigned line_length = 10;
+    while (*++beg != '1')
+      ++line_length;
+
+    // Try to jump directly to the end + 1 through advance.
+    advance(beg, (found - 2) * line_length + 9 + 2);
+  }
+}
+
+int main()
+{
+  test01();
+  return 0;
+}