--- tk8.5-8.5.8.orig/unix/configure
+++ tk8.5-8.5.8/unix/configure
@@ -11070,7 +11070,7 @@
     TCL_STUB_FLAGS="-DUSE_TCL_STUBS"
 fi
 
-TK_LIBRARY='$(prefix)/lib/tk$(VERSION)'
+test -z "$TK_LIBRARY" && TK_LIBRARY='$(prefix)/lib/tk$(VERSION)'
 PRIVATE_INCLUDE_DIR='$(includedir)'
 HTML_DIR='$(DISTDIR)/html'
 TK_PKG_DIR='tk$(VERSION)'
--- tk8.5-8.5.8.orig/unix/configure.in
+++ tk8.5-8.5.8/unix/configure.in
@@ -607,7 +607,7 @@
     TCL_STUB_FLAGS="-DUSE_TCL_STUBS"
 fi
 
-TK_LIBRARY='$(prefix)/lib/tk$(VERSION)'
+test -z "$TK_LIBRARY" && TK_LIBRARY='$(prefix)/lib/tk$(VERSION)'
 PRIVATE_INCLUDE_DIR='$(includedir)'
 HTML_DIR='$(DISTDIR)/html'
 TK_PKG_DIR='tk$(VERSION)'