diff --git a/app/src/main/cpp/skyline/services/fssrv/IFileSystem.cpp b/app/src/main/cpp/skyline/services/fssrv/IFileSystem.cpp
index 3785bff9..2c655984 100644
--- a/app/src/main/cpp/skyline/services/fssrv/IFileSystem.cpp
+++ b/app/src/main/cpp/skyline/services/fssrv/IFileSystem.cpp
@@ -85,4 +85,10 @@ namespace skyline::service::fssrv {
     Result IFileSystem::Commit(type::KSession &session, ipc::IpcRequest &request, ipc::IpcResponse &response) {
         return {};
     }
+
+    Result IFileSystem::GetFreeSpaceSize(type::KSession &session, ipc::IpcRequest &request, ipc::IpcResponse &response) {
+        //TODO: proper implementation for GetFreeSpaceSize
+        response.Push<u64>(90000000);
+        return {};
+    }
 }
diff --git a/app/src/main/cpp/skyline/services/fssrv/IFileSystem.h b/app/src/main/cpp/skyline/services/fssrv/IFileSystem.h
index a9c4a536..f47ab3e9 100644
--- a/app/src/main/cpp/skyline/services/fssrv/IFileSystem.h
+++ b/app/src/main/cpp/skyline/services/fssrv/IFileSystem.h
@@ -61,6 +61,12 @@ namespace skyline::service::fssrv {
          */
         Result Commit(type::KSession &session, ipc::IpcRequest &request, ipc::IpcResponse &response);
 
+        /**
+         * @brief Returns the total free space of the filesystem
+         * @url https://switchbrew.org/wiki/Filesystem_services#GetFreeSpaceSize
+         */
+        Result GetFreeSpaceSize(type::KSession &session, ipc::IpcRequest &request, ipc::IpcResponse &response);
+
         SERVICE_DECL(
             SFUNC(0x0, IFileSystem, CreateFile),
             SFUNC(0x1, IFileSystem, DeleteFile),
@@ -69,7 +75,8 @@ namespace skyline::service::fssrv {
             SFUNC(0x7, IFileSystem, GetEntryType),
             SFUNC(0x8, IFileSystem, OpenFile),
             SFUNC(0x9, IFileSystem, OpenDirectory),
-            SFUNC(0xA, IFileSystem, Commit)
+            SFUNC(0xA, IFileSystem, Commit),
+            SFUNC(0xB, IFileSystem, GetFreeSpaceSize)
         )
     };
 }