diff --git a/dlls/kernel32/kernel32.spec b/dlls/kernel32/kernel32.spec
index ec094c98508..0f474504bfe 100644
--- a/dlls/kernel32/kernel32.spec
+++ b/dlls/kernel32/kernel32.spec
@@ -782,7 +782,7 @@
 @ stdcall GetProcessAffinityMask(long ptr ptr)
 @ stdcall GetProcessDEPPolicy(long ptr ptr)
 @ stdcall GetProcessFlags(long)
-# @ stub GetProcessGroupAffinity
+@ stdcall -import GetProcessGroupAffinity(long ptr ptr)
 @ stdcall -import GetProcessHandleCount(long ptr)
 @ stdcall -import GetProcessHeap()
 @ stdcall -import GetProcessHeaps(long ptr) RtlGetProcessHeaps
diff --git a/dlls/kernelbase/kernelbase.spec b/dlls/kernelbase/kernelbase.spec
index 9a66c5c2ac0..94a648f65aa 100644
--- a/dlls/kernelbase/kernelbase.spec
+++ b/dlls/kernelbase/kernelbase.spec
@@ -623,7 +623,7 @@
 @ stdcall GetProcAddress(long str)
 # @ stub GetProcAddressForCaller
 # @ stub GetProcessDefaultCpuSets
-# @ stub GetProcessGroupAffinity
+@ stdcall GetProcessGroupAffinity(long ptr ptr)
 @ stdcall GetProcessHandleCount(long ptr)
 @ stdcall -norelay GetProcessHeap() kernelbase_GetProcessHeap
 @ stdcall -import GetProcessHeaps(long ptr) RtlGetProcessHeaps
diff --git a/dlls/kernelbase/process.c b/dlls/kernelbase/process.c
index ab89d3bcf31..924fa733e5b 100644
--- a/dlls/kernelbase/process.c
+++ b/dlls/kernelbase/process.c
@@ -804,6 +804,17 @@ DWORD WINAPI DECLSPEC_HOTPATCH GetPriorityClass( HANDLE process )
 }
 
 
+/***********************************************************************
+ *           GetProcessGroupAffinity   (kernelbase.@)
+ */
+BOOL WINAPI DECLSPEC_HOTPATCH GetProcessGroupAffinity( HANDLE process, USHORT *count, USHORT *array )
+{
+    FIXME( "(%p,%p,%p): stub\n", process, count, array );
+    SetLastError( ERROR_CALL_NOT_IMPLEMENTED );
+    return FALSE;
+}
+
+
 /******************************************************************
  *           GetProcessHandleCount   (kernelbase.@)
  */