diff --git a/test/overlay/Makefile b/test/overlay/Makefile
index 2deec929abf..47937e3c108 100644
--- a/test/overlay/Makefile
+++ b/test/overlay/Makefile
@@ -10,5 +10,5 @@ DTC_FLAGS += -@
 
 # DT overlays
 obj-y += test-fdt-base.dtb.o
-obj-y += test-fdt-overlay.dtb.o
-obj-y += test-fdt-overlay-stacked.dtb.o
+obj-y += test-fdt-overlay.dtbo.o
+obj-y += test-fdt-overlay-stacked.dtbo.o
diff --git a/test/overlay/cmd_ut_overlay.c b/test/overlay/cmd_ut_overlay.c
index bcb29a26e21..256afd115d2 100644
--- a/test/overlay/cmd_ut_overlay.c
+++ b/test/overlay/cmd_ut_overlay.c
@@ -21,8 +21,8 @@
 #define FDT_COPY_SIZE	(4 * SZ_1K)
 
 extern u32 __dtb_test_fdt_base_begin;
-extern u32 __dtb_test_fdt_overlay_begin;
-extern u32 __dtb_test_fdt_overlay_stacked_begin;
+extern u32 __dtbo_test_fdt_overlay_begin;
+extern u32 __dtbo_test_fdt_overlay_stacked_begin;
 
 static void *fdt;
 
@@ -216,8 +216,8 @@ int do_ut_overlay(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 	const int n_ents = UNIT_TEST_SUITE_COUNT(overlay_test);
 	struct unit_test_state *uts;
 	void *fdt_base = &__dtb_test_fdt_base_begin;
-	void *fdt_overlay = &__dtb_test_fdt_overlay_begin;
-	void *fdt_overlay_stacked = &__dtb_test_fdt_overlay_stacked_begin;
+	void *fdt_overlay = &__dtbo_test_fdt_overlay_begin;
+	void *fdt_overlay_stacked = &__dtbo_test_fdt_overlay_stacked_begin;
 	void *fdt_overlay_copy, *fdt_overlay_stacked_copy;
 	int ret = -ENOMEM;
 
diff --git a/test/overlay/test-fdt-overlay-stacked.dts b/test/overlay/test-fdt-overlay-stacked.dtso
similarity index 100%
rename from test/overlay/test-fdt-overlay-stacked.dts
rename to test/overlay/test-fdt-overlay-stacked.dtso
diff --git a/test/overlay/test-fdt-overlay.dts b/test/overlay/test-fdt-overlay.dtso
similarity index 100%
rename from test/overlay/test-fdt-overlay.dts
rename to test/overlay/test-fdt-overlay.dtso