diff --git a/Source/Core/Core/HW/WiimoteCommon/WiimoteReport.h b/Source/Core/Core/HW/WiimoteCommon/WiimoteReport.h
index e3ea617c71..cfcc11b102 100644
--- a/Source/Core/Core/HW/WiimoteCommon/WiimoteReport.h
+++ b/Source/Core/Core/HW/WiimoteCommon/WiimoteReport.h
@@ -449,6 +449,13 @@ struct wm_report_core_accel
 };
 static_assert(sizeof(wm_report_core_accel) == 5, "Wrong size");
 
+struct wm_report_core_ext8
+{
+  wm_buttons c;
+  u8 ext[8];
+};
+static_assert(sizeof(wm_report_core_ext8) == 10, "Wrong size");
+
 struct wm_report_core_accel_ir12
 {
   wm_buttons c;
diff --git a/Source/Core/Core/HW/WiimoteReal/IOWin.cpp b/Source/Core/Core/HW/WiimoteReal/IOWin.cpp
index ed9d6d8e13..b0ad431d2d 100644
--- a/Source/Core/Core/HW/WiimoteReal/IOWin.cpp
+++ b/Source/Core/Core/HW/WiimoteReal/IOWin.cpp
@@ -577,6 +577,38 @@ bool WiimoteWindows::IsConnected() const
   return m_dev_handle != nullptr;
 }
 
+// See http://wiibrew.org/wiki/Wiimote for the Report IDs and its sizes
+size_t GetReportSize(u8 report_id)
+{
+  switch (report_id)
+  {
+  case RT_STATUS_REPORT:
+    return sizeof(wm_status_report);
+  case RT_READ_DATA_REPLY:
+    return sizeof(wm_read_data_reply);
+  case RT_ACK_DATA:
+    return sizeof(wm_acknowledge);
+  case RT_REPORT_CORE:
+    return sizeof(wm_report_core);
+  case RT_REPORT_CORE_ACCEL:
+    return sizeof(wm_report_core_accel);
+  case RT_REPORT_CORE_EXT8:
+    return sizeof(wm_report_core_ext8);
+  case RT_REPORT_CORE_ACCEL_IR12:
+    return sizeof(wm_report_core_accel_ir12);
+  case RT_REPORT_CORE_EXT19:
+  case RT_REPORT_CORE_ACCEL_EXT16:
+  case RT_REPORT_CORE_IR10_EXT9:
+  case RT_REPORT_CORE_ACCEL_IR10_EXT6:
+  case RT_REPORT_EXT21:
+  case RT_REPORT_INTERLEAVE1:
+  case RT_REPORT_INTERLEAVE2:
+    return sizeof(wm_report_ext21);
+  default:
+    return 0;
+  }
+}
+
 // positive = read packet
 // negative = didn't read packet
 // zero = error
@@ -624,7 +656,17 @@ int IORead(HANDLE& dev_handle, OVERLAPPED& hid_overlap_read, u8* buf, int index)
     }
   }
 
-  return bytes + 1;
+  // ReadFile will always return 22 bytes read.
+  // So we need to calculate the actual report size by its report ID
+  DWORD report_size = static_cast<DWORD>(GetReportSize(buf[1]));
+  if (report_size == 0)
+  {
+    WARN_LOG(WIIMOTE, "Received unsupported report %d in Wii Remote %i", buf[1], index + 1);
+    return -1;
+  }
+
+  // 1 Byte for the Data Report Byte, another for the Report ID and the actual report size
+  return 1 + 1 + report_size;
 }
 
 void WiimoteWindows::IOWakeup()
@@ -646,15 +688,15 @@ static int IOWritePerSetOutputReport(HANDLE& dev_handle, const u8* buf, size_t l
   if (!result)
   {
     DWORD err = GetLastError();
-    if (err == 121)
+    if (err == ERROR_SEM_TIMEOUT)
     {
-      // Semaphore timeout
       NOTICE_LOG(WIIMOTE, "IOWrite[WWM_SET_OUTPUT_REPORT]: Unable to send data to the Wiimote");
     }
-    else if (err != 0x1F)  // Some third-party adapters (DolphinBar) use this
-                           // error code to signal the absence of a Wiimote
-                           // linked to the HID device.
+    else if (err != ERROR_GEN_FAILURE)
     {
+      // Some third-party adapters (DolphinBar) use this
+      // error code to signal the absence of a Wiimote
+      // linked to the HID device.
       WARN_LOG(WIIMOTE, "IOWrite[WWM_SET_OUTPUT_REPORT]: Error: %08x", err);
     }
   }