diff --git a/libstdc++-v3/include/bits/ostream.tcc b/libstdc++-v3/include/bits/ostream.tcc
index 06b2217d216..614b347736b 100644
--- a/libstdc++-v3/include/bits/ostream.tcc
+++ b/libstdc++-v3/include/bits/ostream.tcc
@@ -195,7 +195,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	  ios_base::iostate __err = ios_base::goodbit;
 	  __try
 	    {
-	      if (this->rdbuf()->sputn(__s, __n) != __n)
+	      if (this->rdbuf()->__buffered_sputn(__s, __n) != __n)
 		__err = ios_base::badbit;
 	    }
 	  __catch(__cxxabiv1::__forced_unwind&)
diff --git a/libstdc++-v3/include/bits/ostream_insert.h b/libstdc++-v3/include/bits/ostream_insert.h
index 72eea8b1d05..650ea1afd9e 100644
--- a/libstdc++-v3/include/bits/ostream_insert.h
+++ b/libstdc++-v3/include/bits/ostream_insert.h
@@ -48,7 +48,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       typedef basic_ostream<_CharT, _Traits>       __ostream_type;      
       typedef typename __ostream_type::ios_base    __ios_base;
 
-      const streamsize __put = __out.rdbuf()->sputn(__s, __n);
+      const streamsize __put = __out.rdbuf()->__buffered_sputn(__s, __n);
       if (__put != __n)
 	__out.setstate(__ios_base::badbit);
     }
diff --git a/libstdc++-v3/include/bits/streambuf.tcc b/libstdc++-v3/include/bits/streambuf.tcc
index 22464c4401c..7e803e4fc08 100644
--- a/libstdc++-v3/include/bits/streambuf.tcc
+++ b/libstdc++-v3/include/bits/streambuf.tcc
@@ -108,6 +108,22 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       return __ret;
     }
 
+  template<typename _CharT, typename _Traits>
+    streamsize
+    basic_streambuf<_CharT, _Traits>::
+    __buffered_sputn(const char_type* __s, streamsize __n)
+  {
+    const streamsize __buf_len = this->epptr() - this->pptr();
+    if (__buf_len >= __n)
+      {
+	traits_type::copy(this->pptr(), __s, __n);
+	this->__safe_pbump(__n);
+	return __n;
+      }
+    else
+      return this->xsputn(__s, __n);
+  }
+
   // Conceivably, this could be used to implement buffer-to-buffer
   // copies, if this was ever desired in an un-ambiguous way by the
   // standard.
diff --git a/libstdc++-v3/include/std/streambuf b/libstdc++-v3/include/std/streambuf
index e213104c4f4..a1a2277adc7 100644
--- a/libstdc++-v3/include/std/streambuf
+++ b/libstdc++-v3/include/std/streambuf
@@ -455,6 +455,20 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       sputn(const char_type* __s, streamsize __n)
       { return this->xsputn(__s, __n); }
 
+      /**
+       *  @brief  Entry point for all single-character output functions.
+       *  @param  __s  A buffer read area.
+       *  @param  __n  A count.
+       *
+       *  Internal output function.
+       *
+       *
+       *  Has the same effect as sputn(__s,__n), but attempts to use the
+       *  existing buffer space rather than make a virtual call, if possible.
+      */
+      streamsize
+      __buffered_sputn(const char_type* __s, streamsize __n);
+
     protected:
       /**
        *  @brief  Base constructor.