diff --git a/dlls/dbghelp/stack.c b/dlls/dbghelp/stack.c
index a95e4b2c5c0..cb18576d926 100644
--- a/dlls/dbghelp/stack.c
+++ b/dlls/dbghelp/stack.c
@@ -32,8 +32,8 @@
 #include "ntstatus.h"
 #include "thread.h" /* FIXME: must be included before winternl.h */
 #include "winternl.h"
+#include "wine/winbase16.h"
 #include "wine/debug.h"
-#include "stackframe.h"
 
 WINE_DEFAULT_DEBUG_CHANNEL(dbghelp);
 
diff --git a/dlls/user/winproc.c b/dlls/user/winproc.c
index 1e1467094aa..dcc00c9d648 100644
--- a/dlls/user/winproc.c
+++ b/dlls/user/winproc.c
@@ -31,7 +31,6 @@
 #include "wownt32.h"
 #include "wine/winbase16.h"
 #include "wine/winuser16.h"
-#include "stackframe.h"
 #include "controls.h"
 #include "win.h"
 #include "winproc.h"
@@ -432,9 +431,17 @@ static LRESULT WINAPI WINPROC_CallWndProc16( WNDPROC16 proc, HWND16 hwnd,
                                              LPARAM lParam )
 {
     CONTEXT86 context;
-    LRESULT ret;
-    WORD args[5];
-    DWORD offset = 0;
+    size_t size = 0;
+    struct
+    {
+        WORD params[5];
+        union
+        {
+            CREATESTRUCT16 cs16;
+            DRAWITEMSTRUCT16 dis16;
+            COMPAREITEMSTRUCT16 cis16;
+        } u;
+    } args;
 
     USER_CheckNotLock();
 
@@ -461,30 +468,26 @@ static LRESULT WINAPI WINPROC_CallWndProc16( WNDPROC16 proc, HWND16 hwnd,
         {
           case WM_CREATE:
           case WM_NCCREATE:
-            offset = sizeof(CREATESTRUCT16); break;
+            size = sizeof(CREATESTRUCT16); break;
           case WM_DRAWITEM:
-            offset = sizeof(DRAWITEMSTRUCT16); break;
+            size = sizeof(DRAWITEMSTRUCT16); break;
           case WM_COMPAREITEM:
-            offset = sizeof(COMPAREITEMSTRUCT16); break;
+            size = sizeof(COMPAREITEMSTRUCT16); break;
         }
-        if (offset)
+        if (size)
         {
-            void *s = MapSL(lParam);
-            lParam = stack16_push( offset );
-            memcpy( MapSL(lParam), s, offset );
+            memcpy( &args.u, MapSL(lParam), size );
+            lParam = (SEGPTR)NtCurrentTeb()->WOW32Reserved - size;
         }
     }
 
-    args[4] = hwnd;
-    args[3] = msg;
-    args[2] = wParam;
-    args[1] = HIWORD(lParam);
-    args[0] = LOWORD(lParam);
-    WOWCallback16Ex( 0, WCB16_REGS, sizeof(args), args, (DWORD *)&context );
-    ret = MAKELONG( LOWORD(context.Eax), LOWORD(context.Edx) );
-
-    if (offset) stack16_pop( offset );
-    return ret;
+    args.params[4] = hwnd;
+    args.params[3] = msg;
+    args.params[2] = wParam;
+    args.params[1] = HIWORD(lParam);
+    args.params[0] = LOWORD(lParam);
+    WOWCallback16Ex( 0, WCB16_REGS, sizeof(args.params) + size, &args, (DWORD *)&context );
+    return MAKELONG( LOWORD(context.Eax), LOWORD(context.Edx) );
 }
 
 
diff --git a/dlls/user/wnd16.c b/dlls/user/wnd16.c
index 1042a5a6cde..20a09022705 100644
--- a/dlls/user/wnd16.c
+++ b/dlls/user/wnd16.c
@@ -22,7 +22,6 @@
 #include "wownt32.h"
 #include "win.h"
 #include "winproc.h"
-#include "stackframe.h"
 #include "user_private.h"
 
 /* handle <--> handle16 conversions */
@@ -357,7 +356,8 @@ HWND16 WINAPI GetParent16( HWND16 hwnd )
  */
 BOOL16 WINAPI IsWindow16( HWND16 hwnd )
 {
-    CURRENT_STACK16->es = USER_HeapSel;
+    STACK16FRAME *frame = MapSL( (SEGPTR)NtCurrentTeb()->WOW32Reserved );
+    frame->es = USER_HeapSel;
     /* don't use WIN_Handle32 here, we don't care about the full handle */
     return IsWindow( HWND_32(hwnd) );
 }
diff --git a/programs/winedbg/stack.c b/programs/winedbg/stack.c
index b41fe605116..a7645561931 100644
--- a/programs/winedbg/stack.c
+++ b/programs/winedbg/stack.c
@@ -25,8 +25,8 @@
 #include <stdlib.h>
 
 #include "debugger.h"
-#include "stackframe.h"
 #include "winbase.h"
+#include "wine/winbase16.h"
 #include "wine/debug.h"
 #include "tlhelp32.h"
 
diff --git a/tools/winebuild/relay.c b/tools/winebuild/relay.c
index 8805b8b95b6..0747da4cfc5 100644
--- a/tools/winebuild/relay.c
+++ b/tools/winebuild/relay.c
@@ -28,7 +28,7 @@
 #include <ctype.h>
 
 #include "thread.h"
-#include "stackframe.h"
+#include "wine/winbase16.h"
 
 #include "build.h"
 
diff --git a/tools/winebuild/spec16.c b/tools/winebuild/spec16.c
index e9584b5f569..41395dcc0fe 100644
--- a/tools/winebuild/spec16.c
+++ b/tools/winebuild/spec16.c
@@ -29,7 +29,7 @@
 #include <ctype.h>
 
 #include "wine/exception.h"
-#include "stackframe.h"
+#include "wine/winbase16.h"
 #include "module.h"
 
 #include "build.h"