diff --git a/dlls/user32/winproc.c b/dlls/user32/winproc.c
index 22874360af0..43d57766616 100644
--- a/dlls/user32/winproc.c
+++ b/dlls/user32/winproc.c
@@ -842,20 +842,8 @@ BOOL unpack_message( HWND hwnd, UINT message, WPARAM *wparam, LPARAM *lparam,
     case EM_REPLACESEL:
     case WM_GETMINMAXINFO:
     case WM_DRAWITEM:
-        break;
     case WM_MEASUREITEM:
-    {
-        MEASUREITEMSTRUCT mis;
-        if (size < sizeof(ps->mis)) return FALSE;
-        mis.CtlType    = ps->mis.CtlType;
-        mis.CtlID      = ps->mis.CtlID;
-        mis.itemID     = ps->mis.itemID;
-        mis.itemWidth  = ps->mis.itemWidth;
-        mis.itemHeight = ps->mis.itemHeight;
-        mis.itemData   = (ULONG_PTR)unpack_ptr( ps->mis.itemData );
-        memcpy( *buffer, &mis, sizeof(mis) );
         break;
-    }
     case WM_DELETEITEM:
     {
         DELETEITEMSTRUCT dls;
@@ -1171,6 +1159,7 @@ BOOL WINAPI User32CallWindowProc( struct win_proc_params *params, ULONG size )
         case LB_ADDFILE:
         case EM_REPLACESEL:
         case WM_GETMINMAXINFO:
+        case WM_MEASUREITEM:
         {
             LRESULT *result_ptr = (LRESULT *)buffer - 1;
             *result_ptr = result;
diff --git a/dlls/win32u/message.c b/dlls/win32u/message.c
index 679e349f817..fe2e1c77400 100644
--- a/dlls/win32u/message.c
+++ b/dlls/win32u/message.c
@@ -449,6 +449,19 @@ static BOOL unpack_message( HWND hwnd, UINT message, WPARAM *wparam, LPARAM *lpa
         memcpy( *buffer, &dis, sizeof(dis) );
         break;
     }
+    case WM_MEASUREITEM:
+    {
+        MEASUREITEMSTRUCT mis;
+        if (size < sizeof(ps->mis)) return FALSE;
+        mis.CtlType    = ps->mis.CtlType;
+        mis.CtlID      = ps->mis.CtlID;
+        mis.itemID     = ps->mis.itemID;
+        mis.itemWidth  = ps->mis.itemWidth;
+        mis.itemHeight = ps->mis.itemHeight;
+        mis.itemData   = (ULONG_PTR)unpack_ptr( ps->mis.itemData );
+        memcpy( *buffer, &mis, sizeof(mis) );
+        break;
+    }
     case WM_WINE_SETWINDOWPOS:
     {
         WINDOWPOS wp;
@@ -1239,6 +1252,9 @@ size_t user_message_size( UINT message, WPARAM wparam, LPARAM lparam, BOOL other
     case WM_DRAWITEM:
         size = sizeof(DRAWITEMSTRUCT);
         break;
+    case WM_MEASUREITEM:
+        size = sizeof(MEASUREITEMSTRUCT);
+        break;
     }
 
     return size;
@@ -1353,6 +1369,9 @@ static void copy_user_result( void *buffer, size_t size, LRESULT result, UINT me
     case WM_GETMINMAXINFO:
         copy_size = sizeof(MINMAXINFO);
         break;
+    case WM_MEASUREITEM:
+        copy_size = sizeof(MEASUREITEMSTRUCT);
+        break;
     default:
         return;
     }
@@ -1377,9 +1396,6 @@ static void copy_reply( LRESULT result, HWND hwnd, UINT message, WPARAM wparam,
     case LB_GETTEXT:
         copy_size = (result + 1) * sizeof(WCHAR);
         break;
-    case WM_MEASUREITEM:
-        copy_size = sizeof(MEASUREITEMSTRUCT);
-        break;
     case WM_WINDOWPOSCHANGING:
     case WM_WINDOWPOSCHANGED:
         copy_size = sizeof(WINDOWPOS);
diff --git a/dlls/win32u/tests/win32u.c b/dlls/win32u/tests/win32u.c
index 0fa46a57c2e..8008e6aff10 100644
--- a/dlls/win32u/tests/win32u.c
+++ b/dlls/win32u/tests/win32u.c
@@ -1622,6 +1622,8 @@ static void test_wndproc_hook(void)
     static const MINMAXINFO minmax_in = { .ptMinTrackSize.x = 1 };
     static const MINMAXINFO minmax_out = { .ptMinTrackSize.x = 2 };
     static const DRAWITEMSTRUCT drawitem_in = { .itemID = 1 };
+    static const MEASUREITEMSTRUCT mis_in = { .itemID = 1 };
+    static const MEASUREITEMSTRUCT mis_out = { .itemID = 2, .CtlType = 3, .CtlID = 4, .itemData = 5 };
 
     static const struct lparam_hook_test lparam_hook_tests[] =
     {
@@ -1711,6 +1713,11 @@ static void test_wndproc_hook(void)
             .lparam_size = sizeof(minmax_in), .lparam = &minmax_in, .change_lparam = &minmax_out,
             .check_size = sizeof(minmax_in)
         },
+        {
+            "WM_MEASUREITEM", WM_MEASUREITEM, .wparam = 10,
+            .lparam_size = sizeof(mis_in), .lparam = &mis_in, .change_lparam = &mis_out,
+            .check_size = sizeof(mis_in),
+        },
         /* messages that don't change lparam */
         { "WM_USER", WM_USER },
         { "WM_NOTIFY", WM_NOTIFY },
diff --git a/dlls/wow64win/user.c b/dlls/wow64win/user.c
index 32dea8e84ac..937ceea5b90 100644
--- a/dlls/wow64win/user.c
+++ b/dlls/wow64win/user.c
@@ -669,6 +669,21 @@ static size_t packed_message_64to32( UINT message, WPARAM wparam,
             memcpy( params32, &dis32, sizeof(dis32) );
             return sizeof(dis32);
         }
+
+    case WM_MEASUREITEM:
+        {
+            MEASUREITEMSTRUCT32 mis32;
+            const MEASUREITEMSTRUCT *mis64 = params64;
+
+            mis32.CtlType    = mis64->CtlType;
+            mis32.CtlID      = mis64->CtlID;
+            mis32.itemID     = mis64->itemID;
+            mis32.itemWidth  = mis64->itemWidth;
+            mis32.itemHeight = mis64->itemHeight;
+            mis32.itemData   = mis64->itemData;
+            memcpy( params32, &mis32, sizeof(mis32) );
+            return sizeof(mis32);
+        }
     }
 
     memmove( params32, params64, size );
@@ -716,6 +731,20 @@ static size_t packed_result_32to64( UINT message, WPARAM wparam, const void *par
         }
         break;
 
+    case WM_MEASUREITEM:
+        {
+            const MEASUREITEMSTRUCT32 *mis32 = params32;
+            MEASUREITEMSTRUCT *mis64 = params64;
+
+            mis64->CtlType    = mis32->CtlType;
+            mis64->CtlID      = mis32->CtlID;
+            mis64->itemID     = mis32->itemID;
+            mis64->itemWidth  = mis32->itemWidth;
+            mis64->itemHeight = mis32->itemHeight;
+            mis64->itemData   = mis32->itemData;
+            return sizeof(*mis64);
+        }
+
     case WM_GETTEXT:
     case WM_ASKCBFORMATNAME:
     case WM_GETMINMAXINFO:
@@ -3155,8 +3184,12 @@ static LRESULT message_call_32to64( HWND hwnd, UINT msg, WPARAM wparam, LPARAM l
             mis.itemHeight = mis32->itemHeight;
             mis.itemData   = mis32->itemData;
             ret = NtUserMessageCall( hwnd, msg, wparam, (LPARAM)&mis, result_info, type, ansi );
+            mis32->CtlType    = mis.CtlType;
+            mis32->CtlID      = mis.CtlID;
+            mis32->itemID     = mis.itemID;
             mis32->itemWidth  = mis.itemWidth;
             mis32->itemHeight = mis.itemHeight;
+            mis32->itemData   = mis.itemData;
             return ret;
         }