diff --git a/render.c b/render.c
index 2eab275e..c4ea9bc6 100644
--- a/render.c
+++ b/render.c
@@ -602,14 +602,6 @@ grid_render_scroll(struct terminal *term, struct buffer *buf,
             term->wl->shm, buf, dmg->scroll.lines * term->cell_height,
             term->margins.top, dmg->scroll.region.start * term->cell_height,
             term->margins.bottom, (term->rows - dmg->scroll.region.end) * term->cell_height);
-
-        if (!did_shm_scroll)
-            LOG_DBG("fast scroll failed");
-    } else {
-        LOG_DBG(
-            "skipping SHM scroll "
-            "(region.start=%d, bottom-region-lines=%d, term-lines=%d)",
-            dmb->scroll.region.start, scroll_region_lines, term->rows);
     }
 
     if (did_shm_scroll) {
@@ -647,26 +639,65 @@ static void
 grid_render_scroll_reverse(struct terminal *term, struct buffer *buf,
                            const struct damage *dmg)
 {
-    int src_y = term->margins.top + (dmg->scroll.region.start + 0) * term->cell_height;
-    int dst_y = term->margins.top + (dmg->scroll.region.start + dmg->scroll.lines) * term->cell_height;
     int height = (dmg->scroll.region.end - dmg->scroll.region.start - dmg->scroll.lines) * term->cell_height;
 
-    LOG_DBG("damage: SCROLL REVERSE: %d-%d by %d lines (dst-y: %d, src-y: %d, "
-            "height: %d, stride: %d, mmap-size: %zu)",
-            dmg->scroll.region.start, dmg->scroll.region.end,
-            dmg->scroll.lines,
-            dst_y, src_y, height, buf->stride,
-            buf->size);
+    LOG_DBG(
+        "damage: SCROLL REVERSE: %d-%d by %d lines"m
+        dmg->scroll.region.start, dmg->scroll.region.end, dmg->scroll.lines);
 
-    if (height > 0) {
+    if (height <= 0)
+        return;
+
+#if TIME_SCROLL_DAMAGE
+    struct timeval start_time;
+    gettimeofday(&start_time, NULL);
+#endif
+
+    int src_y = term->margins.top + (dmg->scroll.region.start + 0) * term->cell_height;
+    int dst_y = term->margins.top + (dmg->scroll.region.start + dmg->scroll.lines) * term->cell_height;
+
+    bool try_shm_scroll =
+        shm_can_scroll() && (dmg->scroll.lines +
+                             dmg->scroll.region.start +
+                             (term->rows - dmg->scroll.region.end)) < term->rows / 2;
+
+    bool did_shm_scroll = false;
+
+    if (try_shm_scroll) {
+        did_shm_scroll = shm_scroll(
+            term->wl->shm, buf, -dmg->scroll.lines * term->cell_height,
+            term->margins.top, dmg->scroll.region.start * term->cell_height,
+            term->margins.bottom, (term->rows - dmg->scroll.region.end) * term->cell_height);
+    }
+
+    if (did_shm_scroll) {
+        /* Restore margins */
+        render_margin(
+            term, buf, dmg->scroll.region.start, dmg->scroll.region.start + dmg->scroll.lines,
+            true, true);
+    } else {
+        /* Fallback for when we either cannot do SHM scrolling, or it failed */
         uint8_t *raw = buf->mmapped;
         memmove(raw + dst_y * buf->stride,
                 raw + src_y * buf->stride,
                 height * buf->stride);
-
-        wl_surface_damage_buffer(
-            term->window->surface, term->margins.left, dst_y, term->width - term->margins.left - term->margins.right, height);
     }
+
+#if TIME_SCROLL_DAMAGE
+    struct timeval end_time;
+    gettimeofday(&end_time, NULL);
+
+    struct timeval memmove_time;
+    timersub(&end_time, &start_time, &memmove_time);
+    LOG_INFO("scrolled REVERSE %dKB (%d lines) using %s in %lds %ldus",
+             height * buf->stride / 1024, dmg->scroll.lines,
+             did_shm_scroll ? "SHM" : try_shm_scroll ? "memmove (SHM failed)" :  "memmove",
+             memmove_time.tv_sec, memmove_time.tv_usec);
+#endif
+
+    wl_surface_damage_buffer(
+        term->window->surface, term->margins.left, dst_y,
+        term->width - term->margins.left - term->margins.right, height);
 }
 
 static void
diff --git a/shm.c b/shm.c
index d05210a2..1f2bd1a6 100644
--- a/shm.c
+++ b/shm.c
@@ -64,8 +64,6 @@ instantiate_offset(struct wl_shm *shm, struct buffer *buf, size_t new_offset)
     assert(buf->wl_buf == NULL);
     assert(buf->pix == NULL);
 
-    assert(new_offset >= buf->offset);
-
     static size_t page_size = 0;
     if (page_size == 0) {
         page_size = sysconf(_SC_PAGE_SIZE);
@@ -286,10 +284,10 @@ shm_can_scroll(void)
     return can_punch_hole;
 }
 
-bool
-shm_scroll(struct wl_shm *shm, struct buffer *buf, int rows,
-           int top_margin, int top_keep_rows,
-           int bottom_margin, int bottom_keep_rows)
+static bool
+shm_scroll_forward(struct wl_shm *shm, struct buffer *buf, int rows,
+                   int top_margin, int top_keep_rows,
+                   int bottom_margin, int bottom_keep_rows)
 {
     assert(can_punch_hole);
     assert(buf->busy);
@@ -365,7 +363,6 @@ shm_scroll(struct wl_shm *shm, struct buffer *buf, int rows,
     LOG_INFO("PUNCH HOLE: %lds %ldus", tot.tv_sec, tot.tv_usec);
 #endif
 
-
     bool ret = instantiate_offset(shm, buf, new_offset);
 
     if (ret && bottom_keep_rows > 0) {
@@ -387,7 +384,94 @@ shm_scroll(struct wl_shm *shm, struct buffer *buf, int rows,
     return ret;
 }
 
-void
+static bool
+shm_scroll_reverse(struct wl_shm *shm, struct buffer *buf, int rows,
+                   int top_margin, int top_keep_rows,
+                   int bottom_margin, int bottom_keep_rows)
+{
+    assert(rows > 0);
+
+    size_t diff = rows * buf->stride;
+    if (diff > buf->offset)
+        return false;
+
+    const size_t new_offset = buf->offset - rows * buf->stride;
+    assert(new_offset < buf->offset);
+
+#if TIME_SCROLL
+    struct timeval time0;
+    gettimeofday(&time0, NULL);
+
+    struct timeval tot;
+    struct timeval time1 = time0;
+#endif
+
+    if (bottom_keep_rows > 0) {
+        /* Copy 'bottom' region to its new location */
+        memmove(
+            (uint8_t *)buf->mmapped + buf->size - (bottom_margin + rows + bottom_keep_rows) * buf->stride,
+            (uint8_t *)buf->mmapped + buf->size - (bottom_margin + bottom_keep_rows) * buf->stride,
+            bottom_keep_rows * buf->stride);
+
+#if TIME_SCROLL
+        gettimeofday(&time1, NULL);
+        timersub(&time1, &time0, &tot);
+        LOG_INFO("memmove (bottom region): %lds %ldus", tot.tv_sec, tot.tv_usec);
+#endif
+    }
+
+    /* Destroy old objects (they point to the old offset) */
+    pixman_image_unref(buf->pix);
+    wl_buffer_destroy(buf->wl_buf);
+    munmap(buf->real_mmapped, buf->mmap_size);
+
+    buf->pix = NULL;
+    buf->wl_buf = NULL;
+    buf->real_mmapped = buf->mmapped = NULL;
+
+    if (ftruncate(buf->fd, new_offset + buf->size) < 0) {
+        abort();
+    }
+
+#if TIME_SCROLL
+    struct timeval time2;
+    gettimeofday(&time2, NULL);
+    timersub(&time2, &time1, &tot);
+    LOG_INFO("ftruncate: %lds %ldus", tot.tv_sec, tot.tv_usec);
+#endif
+
+    bool ret = instantiate_offset(shm, buf, new_offset);
+
+    if (ret && top_keep_rows > 0) {
+        /* Copy current 'top' region to its new location */
+        memmove(
+            (uint8_t *)buf->mmapped + (top_margin + 0) * buf->stride,
+            (uint8_t *)buf->mmapped + (top_margin + rows) * buf->stride,
+            top_keep_rows * buf->stride);
+
+#if TIME_SCROLL
+        struct timeval time3;
+        gettimeofday(&time3, NULL);
+        timersub(&time3, &time2, &tot);
+        LOG_INFO("memmove (top region): %lds %ldus", tot.tv_sec, tot.tv_usec);
+#endif
+    }
+
+    return ret;
+}
+
+bool
+shm_scroll(struct wl_shm *shm, struct buffer *buf, int rows,
+           int top_margin, int top_keep_rows,
+           int bottom_margin, int bottom_keep_rows)
+{
+    assert(rows != 0);
+    return rows > 0
+        ? shm_scroll_forward(shm, buf, rows, top_margin, top_keep_rows, bottom_margin, bottom_keep_rows)
+        : shm_scroll_reverse(shm, buf, -rows, top_margin, top_keep_rows, bottom_margin, bottom_keep_rows);
+}
+
+    void
 shm_purge(struct wl_shm *shm, unsigned long cookie)
 {
     LOG_DBG("cookie=%lx: purging all buffers", cookie);