diff --git a/WeaselUI/WeaselPanel.cpp b/WeaselUI/WeaselPanel.cpp
index 4e52ba8c4..faed8f410 100644
--- a/WeaselUI/WeaselPanel.cpp
+++ b/WeaselUI/WeaselPanel.cpp
@@ -1156,6 +1156,8 @@ LRESULT WeaselPanel::OnDestroy(UINT uMsg,
   m_hoverIndex = -1;
   m_lastMousePos = {-1, -1};
   m_sticky = false;
+  m_lastWindowPos = {-1, -1};
+  m_hasLastWindowPos = false;
   delete m_layout;
   m_layout = NULL;
   return 0;
@@ -1287,6 +1289,11 @@ void WeaselPanel::_RepositionWindow(const bool& adj) {
     y = rcWorkArea.top;  // over workarea top
   // memorize adjusted position (to avoid window bouncing on height change)
   m_inputPos.bottom = y;
+  if (m_hasLastWindowPos && m_lastWindowPos.x == x && m_lastWindowPos.y == y &&
+      !m_redraw_by_monitor_change)
+    return;
+  m_lastWindowPos = {x, y};
+  m_hasLastWindowPos = true;
   SetWindowPos(HWND_TOPMOST, x, y, 0, 0,
                SWP_NOSIZE | SWP_NOACTIVATE | SWP_NOREDRAW);
 }
diff --git a/WeaselUI/WeaselPanel.h b/WeaselUI/WeaselPanel.h
index 7ad3af77b..82df11241 100644
--- a/WeaselUI/WeaselPanel.h
+++ b/WeaselUI/WeaselPanel.h
@@ -113,6 +113,8 @@ class WeaselPanel
   const bool& m_in_server;
 
   CRect m_inputPos;
+  CPoint m_lastWindowPos = {-1, -1};
+  bool m_hasLastWindowPos = false;
   int m_offsetys[MAX_CANDIDATES_COUNT];  // offset y for candidates when
                                          // vertical layout over bottom
   int m_offsety_preedit;
diff --git a/WeaselUI/WeaselUI.cpp b/WeaselUI/WeaselUI.cpp
index 53a9b92fe..906a1fa08 100644
--- a/WeaselUI/WeaselUI.cpp
+++ b/WeaselUI/WeaselUI.cpp
@@ -39,23 +39,29 @@ UINT_PTR UIImpl::timer = 0;
 void UIImpl::Show() {
   if (!panel.IsWindow())
     return;
-  panel.ShowWindow(SW_SHOWNA);
+  bool already_shown = shown && panel.IsWindowVisible();
   shown = true;
   if (timer) {
     KillTimer(panel.m_hWnd, AUTOHIDE_TIMER);
     timer = 0;
   }
+  if (already_shown)
+    return;
+  panel.ShowWindow(SW_SHOWNA);
 }
 
 void UIImpl::Hide() {
   if (!panel.IsWindow())
     return;
-  panel.ShowWindow(SW_HIDE);
+  bool already_hidden = !shown && !panel.IsWindowVisible();
   shown = false;
   if (timer) {
     KillTimer(panel.m_hWnd, AUTOHIDE_TIMER);
     timer = 0;
   }
+  if (already_hidden)
+    return;
+  panel.ShowWindow(SW_HIDE);
 }
 
 void UIImpl::ShowWithTimeout(size_t millisec) {