diff --git a/configure.ac b/configure.ac
index 39a4bdc..826df24 100644
--- a/configure.ac
+++ b/configure.ac
@@ -7,7 +7,7 @@ AC_CONFIG_SRCDIR([src/solvespace.cpp])
 AC_CONFIG_AUX_DIR([ac-aux])
 AC_CONFIG_MACRO_DIR([m4])
 
-AM_INIT_AUTOMAKE([1.9.6 -Wall -Werror foreign tar-ustar])
+AM_INIT_AUTOMAKE([1.9.6 -Wall -Werror foreign subdir-objects tar-ustar])
 AM_MAINTAINER_MODE
 
 AC_PROG_CC
diff --git a/exposed/Makefile.am b/exposed/Makefile.am
index 036dca9..cc57cef 100644
--- a/exposed/Makefile.am
+++ b/exposed/Makefile.am
@@ -1,7 +1,5 @@
 ## exposed/Makefile.am
 
-AUTOMAKE_OPTIONS = subdir-objects
-
 AM_CPPFLAGS = -I$(top_srcdir)/include
 
 AM_LDFLAGS = -L../src
diff --git a/src/Makefile.am b/src/Makefile.am
index 2a18fe1..c0b8ebb 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,7 +1,5 @@
 ## src/Makefile.am
 
-AUTOMAKE_OPTIONS = subdir-objects
-
 noinst_LIBRARIES = libslvs.a
 
 libslvs_a_SOURCES = \