diff --git a/src/lib-sievestorage/Makefile.am b/src/lib-sievestorage/Makefile.am
index c9f3b82c992c956e9dc87c437f7560dba34a1b2c..67ff30a2ff808b580222e8d9acfb65fcfc44e1b1 100644
--- a/src/lib-sievestorage/Makefile.am
+++ b/src/lib-sievestorage/Makefile.am
@@ -1,6 +1,6 @@
 noinst_LTLIBRARIES = libsievestorage.la
 
-INCLUDES = \
+AM_CPPFLAGS = \
 	$(LIBDOVECOT_INCLUDE) \
 	-I$(top_srcdir) \
 	-I$(top_srcdir)/src/lib-sieve