diff --git a/Makefile.am b/Makefile.am
index 8ae6881..a8eaac9 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -38,6 +38,7 @@ src_bin_eruler_LDADD = @ERULER_LIBS@
 src_bin_eruler_CPPFLAGS = \
 -I$(top_builddir) \
 -DPACKAGE_BIN_DIR=\"$(bindir)\" \
+-DPACKAGE_LIB_DIR=\"$(libdir)\" \
 -DPACKAGE_DATA_DIR=\"$(pkgdatadir)\" \
 @ERULER_CFLAGS@