diff --git a/src/lib-sievestorage/Makefile.am b/src/lib-sievestorage/Makefile.am
index 181971db2ed8d1d03df1cd604073764da3580dae..f885437dfc8c5126864a8c8850fabf485ad24b59 100644
--- a/src/lib-sievestorage/Makefile.am
+++ b/src/lib-sievestorage/Makefile.am
@@ -1,6 +1,6 @@
 noinst_LIBRARIES = libsievestorage.a
 
-INCLUDES = \
+AM_CPPFLAGS = \
 	$(LIBDOVECOT_INCLUDE) \
 	-I$(top_srcdir) \
 	-I$(top_srcdir)/src/lib-sieve