--- cvs-local.orig/Makefile
+++ cvs-local/Makefile
@@ -7,12 +7,14 @@
 INSTALL=install
 
 # You may need to change the -I arguments depending on your system
-CFLAGS=-O3 -I/usr/include/tcl8.3/ -I/usr/include/tcl
+CFLAGS=-O3 -I/usr/include/tcl8.5
+
+LIBS = -ltcl8.5
 
 all:	libfilecmp.so.0.0
 
 libfilecmp.so.0.0: filecmp.c
-	$(CC) $(CFLAGS) -shared -o $@ filecmp.c
+	$(CC) $(CFLAGS) -shared -o $@ filecmp.c $(LIBS)
 
 install: dirdiff libfilecmp.so.0.0
 	$(INSTALL) -c dirdiff $(BINDIR)