diff --git a/configure b/configure
index ade4f862a6..304ed53728 100755
--- a/configure
+++ b/configure
@@ -15417,6 +15417,12 @@ eval TCL_LIBS=\"$TCL_LIBS\"
 eval TCL_LIB_SPEC=\"$TCL_LIB_SPEC\"
 eval TCL_SHARED_BUILD=\"$TCL_SHARED_BUILD\"
 
+        # TCL_INCLUDE_SPEC is only provided in Tcl 8.4 and later
+    if test "${TCL_INCLUDE_SPEC+set}" = set; then
+	eval TCL_INCLUDE_SPEC=\"$TCL_INCLUDE_SPEC\"
+    else
+	TCL_INCLUDE_SPEC=''
+    fi
     fi
 
 # Check for Tk configuration script tkConfig.sh
@@ -16435,6 +16441,7 @@ s,@TCL_LIBS@,$TCL_LIBS,;t t
 s,@TCL_LIB_SPEC@,$TCL_LIB_SPEC,;t t
 s,@TCL_SHARED_BUILD@,$TCL_SHARED_BUILD,;t t
 s,@TCL_SHLIB_LD_LIBS@,$TCL_SHLIB_LD_LIBS,;t t
+s,@TCL_INCLUDE_SPEC@,$TCL_INCLUDE_SPEC,;t t
 s,@TK_CONFIG_SH@,$TK_CONFIG_SH,;t t
 s,@TK_LIBS@,$TK_LIBS,;t t
 s,@TK_LIB_SPEC@,$TK_LIB_SPEC,;t t
diff --git a/configure.in b/configure.in
index bd8bc215e7..f5f0bb747d 100644
--- a/configure.in
+++ b/configure.in
@@ -1,5 +1,5 @@
 dnl Process this file with autoconf to produce a configure script.
-dnl $Header: /cvsroot/pgsql/configure.in,v 1.223 2002/12/29 03:56:35 momjian Exp $
+dnl $Header: /cvsroot/pgsql/configure.in,v 1.224 2002/12/30 17:19:49 tgl Exp $
 dnl
 dnl Developers, please strive to achieve this order:
 dnl
@@ -1135,6 +1135,13 @@ if test "$with_tcl" = yes; then
     PGAC_EVAL_TCLCONFIGSH([$TCL_CONFIG_SH],
                           [TCL_LIB_FILE,TCL_LIBS,TCL_LIB_SPEC,TCL_SHARED_BUILD])
     AC_SUBST(TCL_SHLIB_LD_LIBS)dnl don't want to double-evaluate that one
+    # TCL_INCLUDE_SPEC is only provided in Tcl 8.4 and later
+    if test "${TCL_INCLUDE_SPEC+set}" = set; then
+	eval TCL_INCLUDE_SPEC=\"$TCL_INCLUDE_SPEC\"
+    else
+	TCL_INCLUDE_SPEC=''
+    fi
+    AC_SUBST(TCL_INCLUDE_SPEC)dnl
 fi
 
 # Check for Tk configuration script tkConfig.sh
diff --git a/src/Makefile.global.in b/src/Makefile.global.in
index fb4592ec98..fda7cddb85 100644
--- a/src/Makefile.global.in
+++ b/src/Makefile.global.in
@@ -1,5 +1,5 @@
 # -*-makefile-*-
-# $Header: /cvsroot/pgsql/src/Makefile.global.in,v 1.156 2002/11/10 00:37:28 momjian Exp $
+# $Header: /cvsroot/pgsql/src/Makefile.global.in,v 1.157 2002/12/30 17:19:50 tgl Exp $
 
 #------------------------------------------------------------------------------
 # All PostgreSQL makefiles include this file and use the variables it sets,
@@ -144,6 +144,7 @@ TCLSH			= @TCLSH@
 TCL_LIB_FILE		= @TCL_LIB_FILE@
 TCL_LIBS		= @TCL_LIBS@
 TCL_LIB_SPEC		= @TCL_LIB_SPEC@
+TCL_INCLUDE_SPEC	= @TCL_INCLUDE_SPEC@
 TCL_SHARED_BUILD	= @TCL_SHARED_BUILD@
 TCL_SHLIB_LD_LIBS	= @TCL_SHLIB_LD_LIBS@
 
diff --git a/src/bin/pgtclsh/Makefile b/src/bin/pgtclsh/Makefile
index 8847146d7f..3a379fc20b 100644
--- a/src/bin/pgtclsh/Makefile
+++ b/src/bin/pgtclsh/Makefile
@@ -6,7 +6,7 @@
 # Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
 # Portions Copyright (c) 1994, Regents of the University of California
 #
-# $Header: /cvsroot/pgsql/src/bin/pgtclsh/Attic/Makefile,v 1.39 2002/06/20 20:29:42 momjian Exp $
+# $Header: /cvsroot/pgsql/src/bin/pgtclsh/Attic/Makefile,v 1.40 2002/12/30 17:19:51 tgl Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -19,7 +19,7 @@ libpgtcl_srcdir = $(top_srcdir)/src/interfaces/libpgtcl
 libpgtcl_builddir = $(top_builddir)/src/interfaces/libpgtcl
 libpgtcl = -L$(libpgtcl_builddir) -lpgtcl
 
-override CPPFLAGS := -I$(libpgtcl_srcdir) $(CPPFLAGS) $(TK_XINCLUDES)
+override CPPFLAGS := -I$(libpgtcl_srcdir) $(CPPFLAGS) $(TK_XINCLUDES) $(TCL_INCLUDE_SPEC)
 
 
 # If we are here then Tcl is available
diff --git a/src/interfaces/libpgtcl/Makefile b/src/interfaces/libpgtcl/Makefile
index 6a227cf5ef..63fffeabe2 100644
--- a/src/interfaces/libpgtcl/Makefile
+++ b/src/interfaces/libpgtcl/Makefile
@@ -4,7 +4,7 @@
 #
 # Copyright (c) 1994, Regents of the University of California
 #
-# $Header: /cvsroot/pgsql/src/interfaces/libpgtcl/Attic/Makefile,v 1.29 2002/12/11 04:07:39 momjian Exp $
+# $Header: /cvsroot/pgsql/src/interfaces/libpgtcl/Attic/Makefile,v 1.30 2002/12/30 17:19:52 tgl Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -16,7 +16,7 @@ NAME= pgtcl
 SO_MAJOR_VERSION= 2
 SO_MINOR_VERSION= 4
 
-override CPPFLAGS := -I$(libpq_srcdir) $(CPPFLAGS)
+override CPPFLAGS := -I$(libpq_srcdir) $(CPPFLAGS) $(TCL_INCLUDE_SPEC)
 
 OBJS= pgtcl.o pgtclCmds.o pgtclId.o
 
diff --git a/src/pl/tcl/Makefile b/src/pl/tcl/Makefile
index 43f420c7e1..c48671b0b3 100644
--- a/src/pl/tcl/Makefile
+++ b/src/pl/tcl/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for the pltcl shared object
 #
-# $Header: /cvsroot/pgsql/src/pl/tcl/Makefile,v 1.38 2002/05/24 18:10:17 petere Exp $
+# $Header: /cvsroot/pgsql/src/pl/tcl/Makefile,v 1.39 2002/12/30 17:19:54 tgl Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -11,6 +11,9 @@ top_builddir = ../../..
 include $(top_builddir)/src/Makefile.global
 
 
+override CPPFLAGS := $(CPPFLAGS) $(TCL_INCLUDE_SPEC)
+
+
 # Find out whether Tcl was built as a shared library --- if not, we
 # can't link a shared library that depends on it, and have to forget
 # about building pltcl. In Tcl 8, tclConfig.sh sets TCL_SHARED_BUILD