diff --git a/kitty/fonts.c b/kitty/fonts.c
index 754121a31..4b6c446ea 100644
--- a/kitty/fonts.c
+++ b/kitty/fonts.c
@@ -40,7 +40,7 @@ typedef struct RunFont {
 
 static hb_buffer_t *harfbuzz_buffer = NULL;
 static hb_feature_t hb_features[3] = {{0}};
-static char_type shape_buffer[4096] = {0};
+static struct { char_type *codepoints; size_t capacity; } shape_buffer = {0};
 static size_t max_texture_size = 1024, max_array_len = 1024;
 typedef enum { LIGA_FEATURE, DLIG_FEATURE, CALT_FEATURE } HBFeature;
 
@@ -1105,14 +1105,17 @@ static void
 load_hb_buffer(CPUCell *first_cpu_cell, index_type num_cells, const TextCache *tc, ListOfChars *lc) {
     size_t num = 0;
     hb_buffer_clear_contents(harfbuzz_buffer);
+    // Although hb_buffer_add_codepoints is supposedly an append, we have to
+    // add all text in one call otherwise it breaks shaping, presumably because
+    // of context??
     for (; num_cells; first_cpu_cell++, num_cells--) {
         if (first_cpu_cell->is_multicell && first_cpu_cell->x) continue;
         text_in_cell(first_cpu_cell, tc, lc);
-        const size_t count = MIN(lc->count, arraysz(shape_buffer) - num);
-        memcpy(shape_buffer + num, lc->chars, count * sizeof(shape_buffer[0]));
-        num += count;
+        ensure_space_for((&shape_buffer), codepoints, char_type, lc->count + num, capacity, 512, false);
+        memcpy(shape_buffer.codepoints + num, lc->chars, lc->count * sizeof(shape_buffer.codepoints[0]));
+        num += lc->count;
     }
-    hb_buffer_add_codepoints(harfbuzz_buffer, shape_buffer, num, 0, num);
+    hb_buffer_add_codepoints(harfbuzz_buffer, shape_buffer.codepoints, num, 0, num);
     hb_buffer_guess_segment_properties(harfbuzz_buffer);
     if (OPT(force_ltr)) hb_buffer_set_direction(harfbuzz_buffer, HB_DIRECTION_LTR);
 }
@@ -2055,6 +2058,7 @@ finalize(void) {
     free(global_glyph_render_scratch.sprite_positions);
     if (global_glyph_render_scratch.lc) { cleanup_list_of_chars(global_glyph_render_scratch.lc); free(global_glyph_render_scratch.lc); }
     global_glyph_render_scratch = (GlyphRenderScratch){0};
+    free(shape_buffer.codepoints); zero_at_ptr(&shape_buffer);
 }
 
 static PyObject*