diff --git a/dlls/user32/winproc.c b/dlls/user32/winproc.c
index 1363aad3340..8d6f89eaa6f 100644
--- a/dlls/user32/winproc.c
+++ b/dlls/user32/winproc.c
@@ -853,23 +853,11 @@ BOOL unpack_message( HWND hwnd, UINT message, WPARAM *wparam, LPARAM *lparam,
     case WM_COMPAREITEM:
     case WM_WINDOWPOSCHANGING:
     case WM_WINDOWPOSCHANGED:
+    case WM_HELP:
         break;
     case WM_NOTIFY:
         /* WM_NOTIFY cannot be sent across processes (MSDN) */
         return FALSE;
-    case WM_HELP:
-    {
-        HELPINFO hi;
-        if (size < sizeof(ps->hi)) return FALSE;
-        hi.cbSize       = sizeof(hi);
-        hi.iContextType = ps->hi.iContextType;
-        hi.iCtrlId      = ps->hi.iCtrlId;
-        hi.hItemHandle  = unpack_handle( ps->hi.hItemHandle );
-        hi.dwContextId  = (ULONG_PTR)unpack_ptr( ps->hi.dwContextId );
-        hi.MousePos     = ps->hi.MousePos;
-        memcpy( &ps->hi, &hi, sizeof(hi) );
-        break;
-    }
     case WM_STYLECHANGING:
     case WM_STYLECHANGED:
         minsize = sizeof(STYLESTRUCT);
@@ -1114,6 +1102,7 @@ BOOL WINAPI User32CallWindowProc( struct win_proc_params *params, ULONG size )
         case WM_WINDOWPOSCHANGING:
         case WM_WINDOWPOSCHANGED:
         case WM_COPYDATA:
+        case WM_HELP:
         {
             LRESULT *result_ptr = (LRESULT *)buffer - 1;
             *result_ptr = result;
diff --git a/dlls/win32u/message.c b/dlls/win32u/message.c
index 5cadaa9e75b..7a3acf13ba5 100644
--- a/dlls/win32u/message.c
+++ b/dlls/win32u/message.c
@@ -523,6 +523,19 @@ static BOOL unpack_message( HWND hwnd, UINT message, WPARAM *wparam, LPARAM *lpa
         memcpy( &ps->cds, &cds, sizeof(cds) );
         break;
     }
+    case WM_HELP:
+    {
+        HELPINFO hi;
+        if (size < sizeof(ps->hi)) return FALSE;
+        hi.cbSize       = sizeof(hi);
+        hi.iContextType = ps->hi.iContextType;
+        hi.iCtrlId      = ps->hi.iCtrlId;
+        hi.hItemHandle  = wine_server_ptr_handle( ps->hi.hItemHandle );
+        hi.dwContextId  = (ULONG_PTR)unpack_ptr( ps->hi.dwContextId );
+        hi.MousePos     = ps->hi.MousePos;
+        memcpy( &ps->hi, &hi, sizeof(hi) );
+        break;
+    }
     case WM_WINE_SETWINDOWPOS:
     {
         WINDOWPOS wp;
@@ -1332,6 +1345,9 @@ size_t user_message_size( UINT message, WPARAM wparam, LPARAM lparam, BOOL other
         size = sizeof(*cds) + cds->cbData;
         break;
     }
+    case WM_HELP:
+        size = sizeof(HELPINFO);
+        break;
     }
 
     return size;
diff --git a/dlls/wow64win/user.c b/dlls/wow64win/user.c
index 429854f1950..5914a8d6d4e 100644
--- a/dlls/wow64win/user.c
+++ b/dlls/wow64win/user.c
@@ -218,6 +218,16 @@ typedef struct
     ULONG lpData;
 } COPYDATASTRUCT32;
 
+typedef struct
+{
+    UINT   cbSize;
+    INT    iContextType;
+    INT    iCtrlId;
+    ULONG  hItemHandle;
+    DWORD  dwContextId;
+    POINT  MousePos;
+} HELPINFO32;
+
 typedef struct
 {
     UINT  CtlType;
@@ -734,6 +744,20 @@ static size_t packed_message_64to32( UINT message, WPARAM wparam,
             if (size) memmove( (char *)params32 + sizeof(cds32), cds64 + 1, size );
             return sizeof(cds32) + size;
         }
+    case WM_HELP:
+        {
+            HELPINFO32 hi32;
+            const HELPINFO *hi64 = params64;
+
+            hi32.cbSize       = sizeof(hi32);
+            hi32.iContextType = hi64->iContextType;
+            hi32.iCtrlId      = hi64->iCtrlId;
+            hi32.hItemHandle  = HandleToLong( hi64->hItemHandle );
+            hi32.dwContextId  = hi64->dwContextId;
+            hi32.MousePos     = hi64->MousePos;
+            memcpy( params32, &hi32, sizeof(hi32) );
+            return sizeof(hi32);
+        }
     }
 
     memmove( params32, params64, size );
@@ -3280,6 +3304,20 @@ static LRESULT message_call_32to64( HWND hwnd, UINT msg, WPARAM wparam, LPARAM l
             return NtUserMessageCall( hwnd, msg, wparam, (LPARAM)&cds, result_info, type, ansi );
         }
 
+    case WM_HELP:
+        {
+            HELPINFO32 *hi32 = (void *)lparam;
+            HELPINFO hi64;
+
+            hi64.cbSize       = sizeof(hi64);
+            hi64.iContextType = hi32->iContextType;
+            hi64.iCtrlId      = hi32->iCtrlId;
+            hi64.hItemHandle  = LongToHandle( hi32->hItemHandle );
+            hi64.dwContextId  = hi32->dwContextId;
+            hi64.MousePos     = hi32->MousePos;
+            return NtUserMessageCall( hwnd, msg, wparam, (LPARAM)&hi64, result_info, type, ansi );
+        }
+
     case WM_GETDLGCODE:
         if (lparam)
         {