diff --git a/Source/Core/Core/IOS/SDIO/SDIOSlot0.cpp b/Source/Core/Core/IOS/SDIO/SDIOSlot0.cpp
index df1419a6c01..3500e22d410 100644
--- a/Source/Core/Core/IOS/SDIO/SDIOSlot0.cpp
+++ b/Source/Core/Core/IOS/SDIO/SDIOSlot0.cpp
@@ -309,7 +309,12 @@ s32 SDIOSlot0Device::ExecuteCommand(const Request& request, u32 buffer_in, u32 b
     INFO_LOG_FMT(IOS_SD, "{}Write {} Block(s) from {:#010x} bsize {} to offset {:#010x}!",
                  req.isDMA ? "DMA " : "", req.blocks, req.addr, req.bsize, req.arg);
 
-    if (m_card && Config::Get(Config::MAIN_ALLOW_SD_WRITES))
+    if (!Config::Get(Config::MAIN_ALLOW_SD_WRITES))
+    {
+      ERROR_LOG_FMT(IOS_SD, "Write attempted while locked.");
+      ret = RET_LOCKED;
+    }
+    else if (m_card)
     {
       const u32 size = req.bsize * req.blocks;
       const u64 address = GetAddressFromRequest(req.arg);
diff --git a/Source/Core/Core/IOS/SDIO/SDIOSlot0.h b/Source/Core/Core/IOS/SDIO/SDIOSlot0.h
index 242b8d57cc2..8f5ab32a8e7 100644
--- a/Source/Core/Core/IOS/SDIO/SDIOSlot0.h
+++ b/Source/Core/Core/IOS/SDIO/SDIOSlot0.h
@@ -63,6 +63,7 @@ private:
   {
     RET_OK,
     RET_FAIL,
+    RET_LOCKED = -10,
     RET_EVENT_REGISTER,  // internal state only - not actually returned
   };