diff --git a/dlls/api-ms-win-core-processthreads-l1-1-1/api-ms-win-core-processthreads-l1-1-1.spec b/dlls/api-ms-win-core-processthreads-l1-1-1/api-ms-win-core-processthreads-l1-1-1.spec
index ebbe55fe689..616fa639093 100644
--- a/dlls/api-ms-win-core-processthreads-l1-1-1/api-ms-win-core-processthreads-l1-1-1.spec
+++ b/dlls/api-ms-win-core-processthreads-l1-1-1/api-ms-win-core-processthreads-l1-1-1.spec
@@ -44,7 +44,7 @@
 @ stdcall ResumeThread(long) kernel32.ResumeThread
 @ stdcall SetPriorityClass(long long) kernel32.SetPriorityClass
 @ stdcall SetProcessAffinityUpdateMode(long long) kernel32.SetProcessAffinityUpdateMode
-@ stub SetProcessMitigationPolicy
+@ stdcall SetProcessMitigationPolicy(long ptr long) kernel32.SetProcessMitigationPolicy
 @ stdcall SetProcessShutdownParameters(long long) kernel32.SetProcessShutdownParameters
 @ stdcall SetThreadContext(long ptr) kernel32.SetThreadContext
 @ stdcall SetThreadIdealProcessorEx(long ptr ptr) kernel32.SetThreadIdealProcessorEx
diff --git a/dlls/api-ms-win-core-processthreads-l1-1-2/api-ms-win-core-processthreads-l1-1-2.spec b/dlls/api-ms-win-core-processthreads-l1-1-2/api-ms-win-core-processthreads-l1-1-2.spec
index db94c2e5e7f..8de6c5b66ca 100644
--- a/dlls/api-ms-win-core-processthreads-l1-1-2/api-ms-win-core-processthreads-l1-1-2.spec
+++ b/dlls/api-ms-win-core-processthreads-l1-1-2/api-ms-win-core-processthreads-l1-1-2.spec
@@ -49,7 +49,7 @@
 @ stdcall ResumeThread(long) kernel32.ResumeThread
 @ stdcall SetPriorityClass(long long) kernel32.SetPriorityClass
 @ stdcall SetProcessAffinityUpdateMode(long long) kernel32.SetProcessAffinityUpdateMode
-@ stub SetProcessMitigationPolicy
+@ stdcall SetProcessMitigationPolicy(long ptr long) kernel32.SetProcessMitigationPolicy
 @ stdcall SetProcessPriorityBoost(long long) kernel32.SetProcessPriorityBoost
 @ stdcall SetProcessShutdownParameters(long long) kernel32.SetProcessShutdownParameters
 @ stdcall SetThreadContext(long ptr) kernel32.SetThreadContext
diff --git a/dlls/kernel32/kernel32.spec b/dlls/kernel32/kernel32.spec
index 3060896daa4..c53276c70a2 100644
--- a/dlls/kernel32/kernel32.spec
+++ b/dlls/kernel32/kernel32.spec
@@ -1428,6 +1428,7 @@
 @ stdcall SetProcessAffinityMask(long long)
 @ stdcall SetProcessAffinityUpdateMode(long long)
 @ stdcall SetProcessDEPPolicy(long)
+@ stdcall SetProcessMitigationPolicy(long ptr long)
 # @ stub SetProcessPreferredUILanguages
 @ stdcall SetProcessPriorityBoost(long long)
 @ stdcall SetProcessShutdownParameters(long long)
diff --git a/dlls/kernel32/process.c b/dlls/kernel32/process.c
index 5aa245cf1a6..1a303c58e14 100644
--- a/dlls/kernel32/process.c
+++ b/dlls/kernel32/process.c
@@ -4389,3 +4389,13 @@ BOOL WINAPI BaseFlushAppcompatCache(void)
     SetLastError(ERROR_CALL_NOT_IMPLEMENTED);
     return FALSE;
 }
+
+/**********************************************************************
+ *           SetProcessMitigationPolicy     (KERNEL32.@)
+ */
+BOOL WINAPI SetProcessMitigationPolicy(PROCESS_MITIGATION_POLICY policy, void *buffer, SIZE_T length)
+{
+    FIXME("(%d, %p, %lu): stub\n", policy, buffer, length);
+
+    return TRUE;
+}
diff --git a/dlls/kernelbase/kernelbase.spec b/dlls/kernelbase/kernelbase.spec
index cae825defdf..5865ee7c482 100644
--- a/dlls/kernelbase/kernelbase.spec
+++ b/dlls/kernelbase/kernelbase.spec
@@ -1456,7 +1456,7 @@
 # @ stub SetProcessDefaultCpuSets
 # @ stub SetProcessGroupAffinity
 # @ stub SetProcessInformation
-# @ stub SetProcessMitigationPolicy
+@ stdcall SetProcessMitigationPolicy(long ptr long) kernel32.SetProcessMitigationPolicy
 # @ stub SetProcessPreferredUILanguages
 @ stdcall SetProcessPriorityBoost(long long) kernel32.SetProcessPriorityBoost
 @ stdcall SetProcessShutdownParameters(long long) kernel32.SetProcessShutdownParameters
diff --git a/include/winnt.h b/include/winnt.h
index 7f822c4aec9..c9248a40038 100644
--- a/include/winnt.h
+++ b/include/winnt.h
@@ -6273,6 +6273,26 @@ typedef enum _RTL_UMS_SCHEDULER_REASON
 
 typedef void (CALLBACK *PRTL_UMS_SCHEDULER_ENTRY_POINT)(RTL_UMS_SCHEDULER_REASON,ULONG_PTR,PVOID);
 
+typedef enum _PROCESS_MITIGATION_POLICY
+{
+    ProcessDEPPolicy,
+    ProcessASLRPolicy,
+    ProcessDynamicCodePolicy,
+    ProcessStrictHandleCheckPolicy,
+    ProcessSystemCallDisablePolicy,
+    ProcessMitigationOptionsMask,
+    ProcessExtensionPointDisablePolicy,
+    ProcessControlFlowGuardPolicy,
+    ProcessSignaturePolicy,
+    ProcessFontDisablePolicy,
+    ProcessImageLoadPolicy,
+    ProcessSystemCallFilterPolicy,
+    ProcessPayloadRestrictionPolicy,
+    ProcessChildProcessPolicy,
+    ProcessSideChannelIsolationPolicy,
+    MaxProcessMitigationPolicy
+} PROCESS_MITIGATION_POLICY, *PPROCESS_MITIGATION_POLICY;
+
 #ifdef __cplusplus
 }
 #endif