diff --git a/src/configure.in b/src/configure.in
index c775985..898e79c 100644
--- a/src/configure.in
+++ b/src/configure.in
@@ -794,11 +794,12 @@
 
       AC_MSG_CHECKING(for location of Tcl include)
       if test "x$MACOSX" != "xyes"; then
-	tclinc="$tclloc/include $tclloc/include/tcl $tclloc/include/tcl$tclver /usr/local/include /usr/include"
+	tclinc="$tclloc/include $tclloc/include/tcl $tclloc/include/tcl$tclver /usr/local/include /usr/local/include/tcl$tclver /usr/include /usr/include/tcl$tclver"
       else
 	dnl For Mac OS X 10.3, use the OS-provided framework location
 	tclinc="/System/Library/Frameworks/Tcl.framework/Headers"
       fi
+      TCL_INC=
       for try in $tclinc; do
 	if test -f "$try/tcl.h"; then
 	  AC_MSG_RESULT($try/tcl.h)