diff -ur pgplot.orig/sys_linux/g77_gcc.conf pgplot/sys_linux/g77_gcc.conf
--- pgplot.orig/sys_linux/g77_gcc.conf	1999-07-05 11:10:33.000000000 -0700
+++ pgplot/sys_linux/g77_gcc.conf	2005-12-15 19:59:28.000000000 -0800
@@ -5,7 +5,7 @@
 #           X2DRIV (/xdisp and /figdisp).
 # The arguments needed by the C compiler to locate X-window include files.
  
-   XINCL="-I/usr/X11R6/include"
+#   XINCL="-I/usr/X11R6/include"
 
 # Optional: Needed by XMDRIV (/xmotif).
 # The arguments needed by the C compiler to locate Motif, Xt and
@@ -40,7 +40,8 @@
 # The FORTRAN compiler flags to use when compiling the pgplot library.
 # (NB. makemake prepends -c to $FFLAGC where needed)
  
-   FFLAGC="-u -Wall -fPIC -O"
+   FFLAGOPT="-O"
+   FFLAGC="-u -Wall -fPIC $FFLAGOPT"
 
 # Mandatory.
 # The FORTRAN compiler flags to use when compiling fortran demo programs.
@@ -56,13 +57,14 @@
 
 # Mandatory.
 # The C compiler flags to use when compiling the pgplot library.
- 
-   CFLAGC="-Wall -fPIC -DPG_PPU -O"
+
+   CFLAGOPT="-O"
+   CFLAGC="-Wall -fPIC -DPG_PPU $CFLAGOPT"
 
 # Mandatory.
 # The C compiler flags to use when compiling C demo programs.
  
-   CFLAGD="-Wall -O"
+   CFLAGD="-Wall $CFLAGOPT"
 
 # Optional: Only needed if the cpgplot library is to be compiled.
 # The flags to use when running pgbind to create the C pgplot wrapper
@@ -74,7 +76,7 @@
 # The library-specification flags to use when linking normal pgplot
 # demo programs.
  
-   LIBS="-L/usr/X11R6/lib -lX11"
+   LIBS="-lX11"
 
 # Optional: Needed by XMDRIV (/xmotif).
 # The library-specification flags to use when linking motif