diff --git a/Makefile-decls.am b/Makefile-decls.am
index cd28ba24..a57466cf 100644
--- a/Makefile-decls.am
+++ b/Makefile-decls.am
@@ -16,7 +16,6 @@
 # Boston, MA 02111-1307, USA.
 
 # Common variables
-ACLOCAL_AMFLAGS =
 AM_CPPFLAGS =
 AM_CFLAGS =
 DISTCHECK_CONFIGURE_FLAGS =
diff --git a/Makefile.am b/Makefile.am
index e202f0d7..451237f4 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -17,7 +17,7 @@
 
 include Makefile-decls.am
 
-ACLOCAL_AMFLAGS += -I m4 ${ACLOCAL_FLAGS}
+ACLOCAL_AMFLAGS = -I m4 ${ACLOCAL_FLAGS}
 AM_CPPFLAGS += -DDATADIR='"$(datadir)"' -DLIBEXECDIR='"$(libexecdir)"' \
 	-DOSTREE_FEATURES='"$(OSTREE_FEATURES)"' \
 	-DGLIB_VERSION_MIN_REQUIRED=GLIB_VERSION_2_34 -DGLIB_VERSION_MAX_ALLOWED=GLIB_VERSION_2_34 \