--- a/src/oct-prcstrm.cc
+++ b/src/oct-prcstrm.cc
@@ -29,13 +29,13 @@
 #include "oct-prcstrm.h"
 
 octave_stream
-octave_iprocstream::create (const string& n, ios::openmode arg_md,
+octave_iprocstream::create (const std::string& n, ios::openmode arg_md,
 			    oct_mach_info::float_format flt_fmt)
 {
   return octave_stream (new octave_iprocstream (n, arg_md, flt_fmt));
 }
 
-octave_iprocstream::octave_iprocstream (const string& n,
+octave_iprocstream::octave_iprocstream (const std::string& n,
 					ios::openmode arg_md,
 					oct_mach_info::float_format flt_fmt)
   : octave_istdiostream (n, 0, arg_md, flt_fmt)
@@ -45,7 +45,7 @@
   if (fp)
     {
       delete is;
-      is = new istdiostream (fp);
+      is = new std::istdiostream (fp);
     }
 }
 
@@ -59,13 +59,13 @@
 }
 
 octave_stream
-octave_oprocstream::create (const string& n, ios::openmode arg_md,
+octave_oprocstream::create (const std::string& n, ios::openmode arg_md,
 			    oct_mach_info::float_format flt_fmt)
 {
   return octave_stream (new octave_oprocstream (n, arg_md, flt_fmt));
 }
 
-octave_oprocstream::octave_oprocstream (const string& n,
+octave_oprocstream::octave_oprocstream (const std::string& n,
 					ios::openmode arg_md,
 					oct_mach_info::float_format flt_fmt)
   : octave_ostdiostream (n, 0, arg_md, flt_fmt)
@@ -75,7 +75,7 @@
   if (fp)
     {
       delete os;
-      os = new ostdiostream (fp);
+      os = new std::ostdiostream (fp);
     }
 }