diff --git a/lib/Makefile.tmpl b/lib/Makefile.tmpl
index 59542e71..48692016 100644
--- a/lib/Makefile.tmpl
+++ b/lib/Makefile.tmpl
@@ -37,6 +37,7 @@ libtar_a_LIBADD = $(LIBOBJS) $(ALLOCA)
 libtar_a_DEPENDENCIES = $(libtar_a_LIBADD)
 
 BUILT_SOURCES =
+AM_CPPFLAGS =
 EXTRA_DIST = Makefile.tmpl
 MAINTAINERCLEANFILES =
 MOSTLYCLEANFILES =