--- a/mozglue/misc/WindowsProcessMitigations.cpp
+++ b/mozglue/misc/WindowsProcessMitigations.cpp
@@ -10,44 +10,16 @@
 #include <processthreadsapi.h>
 
 #if (_WIN32_WINNT < 0x0602)
 BOOL WINAPI GetProcessMitigationPolicy(
     HANDLE hProcess, PROCESS_MITIGATION_POLICY MitigationPolicy, PVOID lpBuffer,
     SIZE_T dwLength);
 #endif  // (_WIN32_WINNT < 0x0602)
 
-// MinGW does not have these definitions in winnt.h yet
-#if defined(__MINGW32__)
-constexpr PROCESS_MITIGATION_POLICY ProcessPayloadRestrictionPolicy =
-    static_cast<PROCESS_MITIGATION_POLICY>(12);
-
-typedef struct _PROCESS_MITIGATION_PAYLOAD_RESTRICTION_POLICY {
-  union {
-    DWORD Flags;
-    struct {
-      DWORD EnableExportAddressFilter : 1;
-      DWORD AuditExportAddressFilter : 1;
-      DWORD EnableExportAddressFilterPlus : 1;
-      DWORD AuditExportAddressFilterPlus : 1;
-      DWORD EnableImportAddressFilter : 1;
-      DWORD AuditImportAddressFilter : 1;
-      DWORD EnableRopStackPivot : 1;
-      DWORD AuditRopStackPivot : 1;
-      DWORD EnableRopCallerCheck : 1;
-      DWORD AuditRopCallerCheck : 1;
-      DWORD EnableRopSimExec : 1;
-      DWORD AuditRopSimExec : 1;
-      DWORD ReservedFlags : 20;
-    } DUMMYSTRUCTNAME;
-  } DUMMYUNIONNAME;
-} PROCESS_MITIGATION_PAYLOAD_RESTRICTION_POLICY,
-    *PPROCESS_MITIGATION_PAYLOAD_RESTRICTION_POLICY;
-#endif  // defined(__MINGW32__)
-
 namespace mozilla {
 
 static decltype(&::GetProcessMitigationPolicy)
 FetchGetProcessMitigationPolicyFunc() {
   static const StaticDynamicallyLinkedFunctionPtr<decltype(
       &::GetProcessMitigationPolicy)>
       pGetProcessMitigationPolicy(L"kernel32.dll",
                                   "GetProcessMitigationPolicy");

--- a/taskcluster/ci/fetch/toolchains.yml
+++ b/taskcluster/ci/fetch/toolchains.yml
@@ -360,17 +360,17 @@ fxc2:
         repo: https://github.com/mozilla/fxc2
         revision: 63ad74b7faa7033f2c1be9cc1cd0225241a1a9a5
 
 mingw-w64:
     description: mingw-w64 source code
     fetch:
         type: git
         repo: https://git.code.sf.net/p/mingw-w64/mingw-w64
-        revision: bd8ca6c303658659496d0c440cf9f2baa8f7a5f0
+        revision: 660e09f3cb20f181b6d6435cb623d65a3922a063
 
 libunwind:
     description: libunwind source code
     fetch:
         type: git
         repo: https://github.com/llvm-mirror/libunwind
         revision: efd17a11b0fae29d3414e11e99307e082d4ee949