diff --git a/AUTHORS b/AUTHORS
index fa79733..9aded2a 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -236,3 +236,7 @@ N: Eric Windisch
 E: windisch@nni.com
 D: QW/Q1 tree merging
 D: GL renderer fixes/optimizations
+
+N: Jukka Sorjonen
+E: jukka.sorjonen@asikkala.fi
+D: win32/Borland support
diff --git a/CREDITS b/CREDITS
index c334fa9..bb831f0 100644
--- a/CREDITS
+++ b/CREDITS
@@ -102,6 +102,9 @@ Win32 support:
   Marcus Sundberg <mackan@stacken.kth.se>
   Jason Nelson <jason_nelson@email.msn.com>
 
+Win32/Borland support:
+  Jukka Sorjonen <jukka.sorjonen@asikkala.fi>
+
 CD-ROM support/optimizations:
   Marcus Sundberg <mackan@stacken.kth.se>
   Loring Holden <lsh@cs.brown.edu>
diff --git a/common/d_edge.c b/common/d_edge.c
index 4ae353b..7e36052 100644
--- a/common/d_edge.c
+++ b/common/d_edge.c
@@ -36,7 +36,7 @@
 static int	miplevel;
 
 float		scale_for_mip;
-int			screenwidth;
+extern int             screenwidth;
 int			ubasestep, errorterm, erroradjustup, erroradjustdown;
 int			vstartscan;
 
diff --git a/common/gl_rsurf.c b/common/gl_rsurf.c
index 2ce55b2..7e2656c 100644
--- a/common/gl_rsurf.c
+++ b/common/gl_rsurf.c
@@ -34,7 +34,7 @@
 #include <mathlib.h>
 #include <sys.h>
 
-int			skytexturenum;
+extern int             skytexturenum;
 
 #ifndef GL_RGBA4
 #define	GL_RGBA4	0
diff --git a/common/gl_screen.c b/common/gl_screen.c
index 4ecf552..2054ba9 100644
--- a/common/gl_screen.c
+++ b/common/gl_screen.c
@@ -130,7 +130,7 @@ int                     scr_fullupdate;
 int                     clearconsole;
 int                     clearnotify;
 
-int                     sb_lines;
+extern int              sb_lines;
 
 viddef_t        vid;                            // global video state
 
diff --git a/common/screen.c b/common/screen.c
index 85ecd0e..f458c1a 100644
--- a/common/screen.c
+++ b/common/screen.c
@@ -132,7 +132,7 @@ int			scr_fullupdate;
 int			clearconsole;
 int			clearnotify;
 
-int			sb_lines;
+extern int             sb_lines;
 
 viddef_t	vid;				// global video state