--- src/Makefile.in.orig	2019-02-05 01:45:09 UTC
+++ src/Makefile.in
@@ -346,7 +346,7 @@ target_alias = @target_alias@
 top_build_prefix = @top_build_prefix@
 top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
-AM_CXXFLAGS = -D_THREAD_SAFE -D_GNU_SOURCE -DVERBOSE
+AM_CXXFLAGS = -D_THREAD_SAFE -D_GNU_SOURCE -DVERBOSE -DDATADIR='"$(datadir)"'
 libnumbertext_1_0_includedir = $(includedir)/libnumbertext
 libnumbertext_1_0_include_HEADERS = \
 	Soros.hxx Numbertext.hxx \