--- a/unix/configure.in	2020-12-26 10:39:12.107965844 +0100
+++ b/unix/configure.in	2020-12-26 10:39:44.821378776 +0100
@@ -773,7 +773,7 @@
 
 eval "TCL_LIB_FILE=${TCL_LIB_FILE}"
 
-test -z "$TCL_LIBRARY" && TCL_LIBRARY='$(prefix)/lib/tcl$(VERSION)'
+test -z "$TCL_LIBRARY" && TCL_LIBRARY='$(libdir)/tcl$(VERSION)'
 PRIVATE_INCLUDE_DIR='$(includedir)'
 HTML_DIR='$(DISTDIR)/html'