diff --git a/windows/window.c b/windows/window.c
index eab0aff9..d147b980 100644
--- a/windows/window.c
+++ b/windows/window.c
@@ -2172,6 +2172,7 @@ static LRESULT CALLBACK WndProc(HWND hwnd, UINT message,
     static bool ignore_clip = false;
     static bool fullscr_on_max = false;
     static bool processed_resize = false;
+    static bool in_scrollbar_loop = false;
     static UINT last_mousemove = 0;
     int resize_action;
 
@@ -2226,6 +2227,21 @@ static LRESULT CALLBACK WndProc(HWND hwnd, UINT message,
       case WM_COMMAND:
       case WM_SYSCOMMAND:
         switch (wParam & ~0xF) {       /* low 4 bits reserved to Windows */
+          case SC_VSCROLL:
+          case SC_HSCROLL:
+            if (message == WM_SYSCOMMAND) {
+                /* As per the long comment in WM_VSCROLL handler: give
+                 * this message the default handling, which starts a
+                 * subsidiary message loop, but set a flag so that
+                 * when we're re-entered from that loop, scroll events
+                 * within an interactive scrollbar-drag can be handled
+                 * differently. */
+                in_scrollbar_loop = true;
+                LRESULT result = DefWindowProcW(hwnd, message, wParam, lParam);
+                in_scrollbar_loop = false;
+                return result;
+            }
+            break;
           case IDM_SHOWLOG:
             showeventlog(hwnd);
             break;
@@ -3138,6 +3154,54 @@ static LRESULT CALLBACK WndProc(HWND hwnd, UINT message,
             if (GetScrollInfo(hwnd, SB_VERT, &si) == 0)
                 si.nTrackPos = HIWORD(wParam);
             term_scroll(term, 1, si.nTrackPos);
+
+            if (in_scrollbar_loop) {
+                /*
+                 * Allow window updates to happen during interactive
+                 * scroll.
+                 *
+                 * When the user takes hold of our window's scrollbar
+                 * and wobbles it interactively back and forth, the
+                 * first thing that happens is that this window
+                 * procedure receives WM_SYSCOMMAND / SC_VSCROLL. [1]
+                 * The default handler for that window message starts
+                 * a subsidiary message loop, which continues to run
+                 * until the user lets go of the scrollbar again. All
+                 * WM_VSCROLL / SB_THUMBTRACK messages are generated
+                 * by the handlers within that subsidiary message
+                 * loop.
+                 *
+                 * So, during that time, _our_ message loop is not
+                 * running, which means toplevel callbacks and timers
+                 * and so forth are not happening, which means that
+                 * when we redraw the window and set a timer to clear
+                 * the cooldown flag 20ms later, that timer never
+                 * fires, and we aren't able to keep redrawing the
+                 * window.
+                 *
+                 * The 'obvious' answer would be to seize that
+                 * SYSCOMMAND ourselves and inhibit the default
+                 * handler, so that our message loop carries on
+                 * running. But that would mean we'd have to
+                 * reimplement the whole of the scrollbar handler!
+                 *
+                 * So instead we apply a bodge: set a static variable
+                 * that indicates that we're _in_ that sub-loop, and
+                 * if so, decide it's OK to manually call
+                 * term_update() proper, bypassing the timer and
+                 * cooldown and rate-limiting systems completely,
+                 * whenever we see an SB_THUMBTRACK. This shouldn't
+                 * cause a rate overload, because we're only doing it
+                 * once per UI event!
+                 *
+                 * [1] Actually, there's an extra oddity where
+                 * SC_HSCROLL and SC_VSCROLL have their documented
+                 * values the wrong way round. Many people on the
+                 * Internet have noticed this, e.g.
+                 * https://stackoverflow.com/q/55528397
+                 */
+                term_update(term);
+            }
             break;
           }
         }