diff --git a/simgear/compiler.h b/simgear/compiler.h
index 5465c082..3195702c 100644
--- a/simgear/compiler.h
+++ b/simgear/compiler.h
@@ -111,6 +111,26 @@
 #      define STL_STRSTREAM  <strstream>
 
 #    endif
+#  elif __GNUC__ == 3
+       // g++-3.0.x
+#      define SG_EXPLICIT_FUNCTION_TMPL_ARGS
+#      define SG_NEED_AUTO_PTR
+#      define SG_MEMBER_TEMPLATES
+#      define SG_NAMESPACES
+#      define SG_HAVE_STD
+#      define SG_HAVE_STREAMBUF
+#      define SG_CLASS_PARTIAL_SPECIALIZATION
+#      define SG_HAVE_STD_INCLUDES
+
+#      define STL_ALGORITHM  <algorithm>
+#      define STL_FUNCTIONAL <functional>
+#      define STL_IOMANIP    <iomanip>
+#      define STL_IOSTREAM   <iostream>
+#      define STL_FSTREAM    <fstream>
+#      define STL_STDEXCEPT  <stdexcept>
+#      define STL_STRING     <string>
+#      define STL_STRSTREAM  <strstream>
+
 #  else
 #    error Time to upgrade. GNU compilers < 2.7 not supported
 #  endif
diff --git a/simgear/io/decode_binobj.cxx b/simgear/io/decode_binobj.cxx
index 1af14819..2cae546d 100644
--- a/simgear/io/decode_binobj.cxx
+++ b/simgear/io/decode_binobj.cxx
@@ -1,4 +1,12 @@
+#include <simgear/compiler.h>
+
 #include <unistd.h>
+#include STL_IOSTREAM
+
+#if !defined(SG_HAVE_NATIVE_SGI_COMPILERS)
+SG_USING_STD(cout);
+SG_USING_STD(endl);
+#endif
 
 #include "sg_binobj.hxx"
 
diff --git a/simgear/io/lowtest.cxx b/simgear/io/lowtest.cxx
index e588f2c3..843c13f9 100644
--- a/simgear/io/lowtest.cxx
+++ b/simgear/io/lowtest.cxx
@@ -3,6 +3,12 @@
 #include STL_IOSTREAM
 #include "lowlevel.hxx"
 
+#if !defined(SG_HAVE_NATIVE_SGI_COMPILERS)
+SG_USING_STD(cout);
+SG_USING_STD(endl);
+#endif
+
+
 static const int sgEndianTest = 1;
 #define sgIsLittleEndian (*((char *) &sgEndianTest ) != 0)
 #define sgIsBigEndian    (*((char *) &sgEndianTest ) == 0)
diff --git a/simgear/io/socktest.cxx b/simgear/io/socktest.cxx
index 471f0ad6..38c38a6e 100644
--- a/simgear/io/socktest.cxx
+++ b/simgear/io/socktest.cxx
@@ -1,8 +1,16 @@
+#include <simgear/compiler.h>
+
 #include <unistd.h>
+#include STL_IOSTREAM
 
 #include "sg_socket.hxx"
 #include "lowlevel.hxx"
 
+#if !defined(SG_HAVE_NATIVE_SGI_COMPILERS)
+SG_USING_STD(cout);
+SG_USING_STD(endl);
+#endif
+
 static const int sgEndianTest = 1;
 #define sgIsLittleEndian (*((char *) &sgEndianTest ) != 0)
 #define sgIsBigEndian    (*((char *) &sgEndianTest ) == 0)
diff --git a/simgear/metar/MetarStation.h b/simgear/metar/MetarStation.h
index b6f38762..d551c596 100644
--- a/simgear/metar/MetarStation.h
+++ b/simgear/metar/MetarStation.h
@@ -88,7 +88,7 @@ private:
 		const CMetarStation &rObj );
 			// Assignment operator.  Not implemented.
 
-	friend CMetarStationDB;
+	friend class CMetarStationDB;
 };
 
 
diff --git a/simgear/misc/props_test.cxx b/simgear/misc/props_test.cxx
index 17f82c7e..8d18162d 100644
--- a/simgear/misc/props_test.cxx
+++ b/simgear/misc/props_test.cxx
@@ -10,6 +10,7 @@
 
 #if !defined(SG_HAVE_NATIVE_SGI_COMPILERS)
 SG_USING_STD(cout);
+SG_USING_STD(cerr);
 SG_USING_STD(endl);
 #endif
 
diff --git a/simgear/misc/zfstream.cxx b/simgear/misc/zfstream.cxx
index fc795ee3..d470ec35 100644
--- a/simgear/misc/zfstream.cxx
+++ b/simgear/misc/zfstream.cxx
@@ -41,7 +41,7 @@
 gzfilebuf::gzfilebuf()
     : streambuf(),
       file(NULL),
-#if defined( __MWERKS__ )
+#if defined( __MWERKS__ ) || __GNUC__ > 2
       mode(ios_openmode(0)),
 #else
       mode(0),
diff --git a/simgear/route/routetest.cxx b/simgear/route/routetest.cxx
index 2de066e7..313ed528 100644
--- a/simgear/route/routetest.cxx
+++ b/simgear/route/routetest.cxx
@@ -1,8 +1,16 @@
+#include <simgear/compiler.h>
 #include <simgear/constants.h>
 
+#include STL_IOSTREAM
+
 #include "route.hxx"
 #include "waypoint.hxx"
 
+#if !defined(SG_HAVE_NATIVE_SGI_COMPILERS)
+SG_USING_STD(cout);
+SG_USING_STD(endl);
+#endif
+ 
 int main() {
     SGRoute route;
 
diff --git a/simgear/route/waytest.cxx b/simgear/route/waytest.cxx
index e8825b8e..bc31b9c5 100644
--- a/simgear/route/waytest.cxx
+++ b/simgear/route/waytest.cxx
@@ -1,6 +1,16 @@
+#include <simgear/compiler.h>
 #include <simgear/constants.h>
+
+#include STL_IOSTREAM
+
 #include "waypoint.hxx"
 
+#if !defined(SG_HAVE_NATIVE_SGI_COMPILERS)
+SG_USING_STD(cout);
+SG_USING_STD(endl);
+#endif
+
+
 int main() {
     SGWayPoint a1(-93.216923, 44.880547, 0.0, SGWayPoint::WGS84, "KMSP");
     SGWayPoint a2(-93.216923, 44.880547, 0.0, SGWayPoint::SPHERICAL, "KMSP");
diff --git a/simgear/serial/serial.cxx b/simgear/serial/serial.cxx
index 3fa85bdc..0859122d 100644
--- a/simgear/serial/serial.cxx
+++ b/simgear/serial/serial.cxx
@@ -24,6 +24,8 @@
 
 #include <simgear/compiler.h>
 
+#include STL_IOSTREAM
+
 #ifdef SG_HAVE_STD_INCLUDE
 #  include <cerrno>
 #else
@@ -44,6 +46,11 @@
 
 #include "serial.hxx"
 
+#if !defined(SG_HAVE_NATIVE_SGI_COMPILERS)
+SG_USING_STD(cout);
+SG_USING_STD(endl);
+#endif
+
 
 FGSerialPort::FGSerialPort()
     : dev_open(false)
diff --git a/simgear/serial/testserial.cxx b/simgear/serial/testserial.cxx
index 51735138..d005f32f 100644
--- a/simgear/serial/testserial.cxx
+++ b/simgear/serial/testserial.cxx
@@ -1,9 +1,18 @@
-#include <string>
+#include <simgear/compiler.h>
+
+#include STL_STRING
+#include STL_IOSTREAM
 
 #include <simgear/debug/logstream.hxx>
 
 #include "serial.hxx"
 
+#if !defined(SG_HAVE_NATIVE_SGI_COMPILERS)
+SG_USING_STD(cout);
+SG_USING_STD(endl);
+#endif
+
+
 int main () {
     FGSerialPort port;
     string value;