diff --git a/src/core/hle/service/aoc/aoc_u.cpp b/src/core/hle/service/aoc/aoc_u.cpp
index 84e6d4c1a0..43b2e2ee80 100644
--- a/src/core/hle/service/aoc/aoc_u.cpp
+++ b/src/core/hle/service/aoc/aoc_u.cpp
@@ -125,7 +125,7 @@ AOC_U::AOC_U(Core::System& system_)
         {9, nullptr, "GetAddOnContentLostErrorCode"},
         {10, &AOC_U::GetAddOnContentListChangedEventWithProcessId, "GetAddOnContentListChangedEventWithProcessId"},
         {11, &AOC_U::NotifyMountAddOnContent, "NotifyMountAddOnContent"},
-        {12, nullptr, "NotifyUnmountAddOnContent"},
+        {12, &AOC_U::NotifyUnmountAddOnContent, "NotifyUnmountAddOnContent"},
         {13, nullptr, "IsAddOnContentMountedForDebug"},
         {50, &AOC_U::CheckAddOnContentMountStatus, "CheckAddOnContentMountStatus"},
         {100, &AOC_U::CreateEcPurchasedEventManager, "CreateEcPurchasedEventManager"},
@@ -284,6 +284,13 @@ void AOC_U::NotifyMountAddOnContent(Kernel::HLERequestContext& ctx) {
     rb.Push(ResultSuccess);
 }
 
+void AOC_U::NotifyUnmountAddOnContent(Kernel::HLERequestContext& ctx) {
+    LOG_WARNING(Service_AOC, "(STUBBED) called");
+
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess);
+}
+
 void AOC_U::CheckAddOnContentMountStatus(Kernel::HLERequestContext& ctx) {
     LOG_WARNING(Service_AOC, "(STUBBED) called");
 
diff --git a/src/core/hle/service/aoc/aoc_u.h b/src/core/hle/service/aoc/aoc_u.h
index 88ac7b745d..4b5f7c5f22 100644
--- a/src/core/hle/service/aoc/aoc_u.h
+++ b/src/core/hle/service/aoc/aoc_u.h
@@ -30,6 +30,7 @@ private:
     void GetAddOnContentListChangedEvent(Kernel::HLERequestContext& ctx);
     void GetAddOnContentListChangedEventWithProcessId(Kernel::HLERequestContext& ctx);
     void NotifyMountAddOnContent(Kernel::HLERequestContext& ctx);
+    void NotifyUnmountAddOnContent(Kernel::HLERequestContext& ctx);
     void CheckAddOnContentMountStatus(Kernel::HLERequestContext& ctx);
     void CreateEcPurchasedEventManager(Kernel::HLERequestContext& ctx);
     void CreatePermanentEcPurchasedEventManager(Kernel::HLERequestContext& ctx);