diff --git a/dlls/winsta/main.c b/dlls/winsta/main.c
index 867d3c95f5..71e1ddae33 100644
--- a/dlls/winsta/main.c
+++ b/dlls/winsta/main.c
@@ -67,6 +67,15 @@ BOOLEAN WINAPI WinStationRegisterConsoleNotification( HANDLE server, HWND hwnd,
     return FALSE;
 }
 
+BOOLEAN WINAPI WinStationGetAllProcesses( HANDLE server, ULONG level,
+                                          ULONG *process_count, void *info )
+{
+    FIXME( "%p %u %p %p\n", server, level, process_count, info );
+    *process_count = 0;
+    SetLastError( ERROR_CALL_NOT_IMPLEMENTED );
+    return FALSE;
+}
+
 BOOL WINAPI WinStationGetProcessSid( PVOID a, HANDLE server, DWORD process_id, PFILETIME process_start_time,
                                      PBYTE process_user_sid, PDWORD sid_size)
 {
diff --git a/dlls/winsta/winsta.spec b/dlls/winsta/winsta.spec
index 46162c0292..9505615ee9 100644
--- a/dlls/winsta/winsta.spec
+++ b/dlls/winsta/winsta.spec
@@ -35,7 +35,7 @@
 @ stub WinStationFreeGAPMemory
 @ stub WinStationFreeMemory
 @ stub WinStationGenerateLicense
-@ stub WinStationGetAllProcesses
+@ stdcall WinStationGetAllProcesses(ptr long ptr ptr)
 @ stub WinStationGetLanAdapterNameA
 @ stub WinStationGetLanAdapterNameW
 @ stub WinStationGetMachinePolicy