diff --git a/config/generic.mak.in b/config/generic.mak.in
index 1cb74f5..2e9cabe 100644
--- a/config/generic.mak.in
+++ b/config/generic.mak.in
@@ -46,8 +46,8 @@ AR		= ar cr
 RPC_INCLUDES = @RPC_INCLUDES@
 
 UCB_STATICLIB = 
 
-TCL_INCLUDE = -I/usr/include/tcl8.3
+TCL_INCLUDE = -I${prefix}/include
 TCL_LINKLIB =
 
 #