diff --git a/Makefile.am b/Makefile.am
index 59d6e54..b6878a3 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,4 +1,8 @@
-SUBDIRS=3rdparty src . tests examples
+SUBDIRS=3rdparty src . examples
+
+if HAVE_CHECK
+SUBDIRS += tests
+endif
 
 lib_LTLIBRARIES = libr3.la
 libr3_la_SOURCES =
@@ -13,6 +17,8 @@ ACLOCAL_AMFLAGS=-I m4
 
 if ENABLE_DEBUG
 AM_CFLAGS += -ggdb -fprofile-arcs -ftest-coverage
+else
+AM_CFLAGS += -O2
 endif
 
 if USE_JEMALLOC
diff --git a/src/Makefile.am b/src/Makefile.am
index b39a746..31a3aed 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,4 +1,4 @@
-AM_CFLAGS=$(DEPS_CFLAGS) $(GVC_DEPS_CFLAGS) $(JSONC_CFLAGS) -I$(top_builddir) -I$(top_builddir)/include -I$(top_builddir)/3rdparty  -Wall -std=c99 -O2
+AM_CFLAGS=$(DEPS_CFLAGS) $(GVC_DEPS_CFLAGS) $(JSONC_CFLAGS) -I$(top_builddir) -I$(top_builddir)/include -I$(top_builddir)/3rdparty  -Wall -std=c99
 AM_LDFLAGS=$(DEPS_LIBS) $(GVC_DEPS_LIBS) $(JSONC_LIBS)
 MAYBE_COVERAGE=--coverage