diff --git a/package/apcupsd/apcupsd.mk b/package/apcupsd/apcupsd.mk
index 9e707e1a5a..0e9235d1b3 100644
--- a/package/apcupsd/apcupsd.mk
+++ b/package/apcupsd/apcupsd.mk
@@ -33,7 +33,7 @@ endif
 
 ifeq ($(BR2_PACKAGE_APCUPSD_MODBUS_USB),y)
 APCUPSD_CONF_OPTS += --enable-modbus-usb
-APCUPSD_DEPENDENCIES = libusb libusb-compat
+APCUPSD_DEPENDENCIES += libusb libusb-compat
 else
 APCUPSD_CONF_OPTS += --disable-modbus-usb
 endif
@@ -64,7 +64,7 @@ endif
 
 ifeq ($(BR2_PACKAGE_APCUPSD_USB),y)
 APCUPSD_CONF_OPTS += --enable-usb
-APCUPSD_DEPENDENCIES = libusb libusb-compat
+APCUPSD_DEPENDENCIES += libusb libusb-compat
 else
 APCUPSD_CONF_OPTS += --disable-usb
 endif