diff --git a/ion/src/shared/dummy/usb.cpp b/ion/src/shared/dummy/usb.cpp
index dfe12752e7e..a78f70071cc 100644
--- a/ion/src/shared/dummy/usb.cpp
+++ b/ion/src/shared/dummy/usb.cpp
@@ -15,7 +15,7 @@ bool isEnumerated() {
 void clearEnumerationInterrupt() {
 }
 
-void DFU(bool) {
+void DFU(bool, int) {
 }
 
 void enable() {
diff --git a/ion/src/simulator/3ds/driver/usb.cpp b/ion/src/simulator/3ds/driver/usb.cpp
index 59e83bea5bb..46932894b2c 100644
--- a/ion/src/simulator/3ds/driver/usb.cpp
+++ b/ion/src/simulator/3ds/driver/usb.cpp
@@ -13,7 +13,7 @@ bool Ion::USB::isEnumerated() {
 void Ion::USB::clearEnumerationInterrupt() {
 }
 
-void Ion::USB::DFU(bool) {
+void Ion::USB::DFU(bool, int) {
 }
 
 void Ion::USB::enable() {