diff --git a/Source/exehead/Ui.c b/Source/exehead/Ui.c
index 3c8c0be6..52fffaaf 100644
--- a/Source/exehead/Ui.c
+++ b/Source/exehead/Ui.c
@@ -50,7 +50,7 @@ int progress_bar_pos, progress_bar_len;
 
 static char g_tmp[4096];
 
-static int m_page=-1,m_retcode;
+static int m_page=-1,m_retcode,m_delta;
 static page *g_this_page;
 
 #define NOTIFY_BYE_BYE 'x'
@@ -403,7 +403,6 @@ BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
   if (uMsg == WM_INITDIALOG || uMsg == WM_NOTIFY_OUTER_NEXT)
   {
     page *this_page;
-    int delta = (int) wParam;
     static DLGPROC winprocs[]=
     {
 #ifdef NSIS_CONFIG_LICENSEPAGE
@@ -419,6 +418,8 @@ BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
 #endif
     };
 
+    m_delta = wParam;
+
     if (uMsg == WM_INITDIALOG)
     {
       g_hwnd=hwndDlg;
@@ -430,7 +431,7 @@ BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
       g_quit_flag = ExecuteCodeSegment(g_header->code_onGUIInit,NULL);
 #endif
         //ShowWindow(hwndDlg, SW_SHOW);
-      delta = 1;
+      m_delta = 1;
     }
 
     this_page=g_pages+m_page;
@@ -439,7 +440,7 @@ BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
 #ifdef NSIS_SUPPORT_CODECALLBACKS
       // Call leave function. If Abort used don't move to the next page.
       // But if quit called we must exit now
-      if (delta==1) if (ExecuteCodeSegment(this_page->leavefunc,NULL)) return !g_quit_flag;
+      if (m_delta==1) if (ExecuteCodeSegment(this_page->leavefunc,NULL)) return !g_quit_flag;
 #endif
 
       // if the last page was a custom page, wait for it to finish by itself.
@@ -451,8 +452,8 @@ BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
     NotifyCurWnd(WM_NOTIFY_INIGO_MONTOYA);
 
 nextPage:
-    m_page+=delta;
-    this_page+=delta;
+    m_page+=m_delta;
+    this_page+=m_delta;
 
 #ifdef NSIS_SUPPORT_CODECALLBACKS
     if (m_page==g_blocks[NB_PAGES].num) ExecuteCodeSegment(g_header->code_onInstSuccess,NULL);