--- libsrc/stlgeom/Makefile.in.orig	2016-04-21 10:58:59 UTC
+++ libsrc/stlgeom/Makefile.in
@@ -278,7 +278,7 @@ top_srcdir = @top_srcdir@
 noinst_HEADERS = meshstlsurface.hpp stlgeom.hpp stlline.hpp \
 stltool.hpp stltopology.hpp vsstl.hpp
 
-AM_CPPFLAGS = -I$(top_srcdir)/libsrc/include $(TCL_INCLUDES)
+AM_CPPFLAGS = -I$(top_srcdir)/libsrc/include $(TCL_INCLUDES) $(TK_INCLUDES)
 METASOURCES = AUTO
 lib_LTLIBRARIES = libstl.la $(am__append_1)
 libstl_la_SOURCES = meshstlsurface.cpp stlgeom.cpp stlgeomchart.cpp \