diff --git a/widget/src/windows/GfxInfo.cpp b/widget/src/windows/GfxInfo.cpp
index 793edd8c1a1..6a4a6fb18b8 100644
--- a/widget/src/windows/GfxInfo.cpp
+++ b/widget/src/windows/GfxInfo.cpp
@@ -475,6 +475,8 @@ GfxInfo::Init()
   mAdapterVendorID2 = ParseIDFromDeviceID(mDeviceID2, "VEN_", 4);
   mAdapterDeviceID  = ParseIDFromDeviceID(mDeviceID,  "&DEV_", 4);
   mAdapterDeviceID2 = ParseIDFromDeviceID(mDeviceID2, "&DEV_", 4);
+  mAdapterSubsysID  = ParseIDFromDeviceID(mDeviceID,  "&SUBSYS_", 8);
+  mAdapterSubsysID2 = ParseIDFromDeviceID(mDeviceID2, "&SUBSYS_", 8);
 
   const char *spoofedDriverVersionString = PR_GetEnv("MOZ_GFX_SPOOF_DRIVER_VERSION");
   if (spoofedDriverVersionString) {
@@ -695,6 +697,7 @@ GfxInfo::AddCrashReportAnnotations()
   /* AppendPrintf only supports 32 character strings, mrghh. */
   note.AppendPrintf("AdapterVendorID: %04x, ", vendorID);
   note.AppendPrintf("AdapterDeviceID: %04x, ", deviceID);
+  note.AppendPrintf("AdapterSubsysID: %08x, ", mAdapterSubsysID);
   note.AppendPrintf("AdapterDriverVersion: ");
   note.Append(NS_LossyConvertUTF16toASCII(adapterDriverVersionString));
 
@@ -717,6 +720,7 @@ GfxInfo::AddCrashReportAnnotations()
     GetAdapterDriverVersion2(adapterDriverVersionString2);
     note.AppendPrintf("AdapterVendorID2: %04x, ", vendorID2);
     note.AppendPrintf("AdapterDeviceID2: %04x, ", deviceID2);
+    note.AppendPrintf("AdapterSubsysID2: %08x, ", mAdapterSubsysID2);
     note.AppendPrintf("AdapterDriverVersion2: ");
     note.Append(NS_LossyConvertUTF16toASCII(adapterDriverVersionString2));
   }
diff --git a/widget/src/windows/GfxInfo.h b/widget/src/windows/GfxInfo.h
index 1fbbc03f25d..e6f4c11e8d5 100644
--- a/widget/src/windows/GfxInfo.h
+++ b/widget/src/windows/GfxInfo.h
@@ -102,6 +102,7 @@ private:
   nsString mDeviceKeyDebug;
   PRUint32 mAdapterVendorID;
   PRUint32 mAdapterDeviceID;
+  PRUint32 mAdapterSubsysID;
   nsString mDeviceString2;
   nsString mDriverVersion2;
   nsString mDeviceID2;
@@ -109,6 +110,7 @@ private:
   nsString mDeviceKey2;
   PRUint32 mAdapterVendorID2;
   PRUint32 mAdapterDeviceID2;
+  PRUint32 mAdapterSubsysID2;
   PRUint32 mWindowsVersion;
   PRBool mHasDualGPU;
   PRBool mIsGPU2Active;