diff --git a/tests/gobject/Makefile.am b/tests/gobject/Makefile.am
index 5c3f18bbf..152637b95 100644
--- a/tests/gobject/Makefile.am
+++ b/tests/gobject/Makefile.am
@@ -32,7 +32,7 @@ noinst_PROGRAMS += \
 # Run the 'installed' tests manually in-tree.
 # This will cause them to be built even if installed tests are disabled.
 check_PROGRAMS += $(installed_test_programs) $(installed_test_extra_programs)
-TESTS = $(installed_test_programs)
+TESTS += $(installed_test_programs)
 TESTS_ENVIRONMENT = \
 	LIBCHARSET_ALIAS_DIR=$(top_builddir)/glib/libcharset    \
 	MALLOC_CHECK_=2                                         \
diff --git a/tests/refcount/Makefile.am b/tests/refcount/Makefile.am
index 57af84f83..f9a98dcd7 100644
--- a/tests/refcount/Makefile.am
+++ b/tests/refcount/Makefile.am
@@ -6,7 +6,7 @@ DEFS = -DGLIB_DISABLE_DEPRECATION_WARNINGS
 AM_CFLAGS = -g
 
 # These are not gtester tests, so handle them manually
-TESTS = \
+TESTS += \
 	closures				\
 	objects					\
 	objects2				\